Yesterday afternoon, my wife and I attended the funeral of Darryn Wiebe's grandfather. It was one of the best funerals that I have ever attended, even though I had never met this man. Darryn had told me about him, but I had never met him. What a good time it was to remember this man.
Darryn's grandfather, Bertil Swanson, was never a pastor, yet, he was known far and wide for his love for God and for the Scriptures. He was a carpenter by trade, who worked hard to support his family. He was a generous man at heart, who gave what he had to others. He was a godly man, whose influence went deep into his family. He loved wood-working, gardening and poetry, which were hobbies he used to glorify the Lord. During his life, he had the privilege of being involved with starting two churches. His ministry continued even through his days in at Fairhaven Retirement Center, where he was able to give frequent devotions. He was known for the amount of Scripture that he had committed to memory. He was also known for his consistent devotional life, devouring the Bible, and praying regularly for those in his life. I was especially encouraged to see how greatly he impacted his family, even down to his grandchildren. He has taught them much about the Lord. He experienced (and personified) the blessing of Psalm 1, ...
How blessed is the man who does not walk in the counsel of the wicked, nor stand in the path of sinners, nor sit in the seat of scoffers!
But his delight is in the law of the LORD, and in His law he meditates day and night.
He will be like a tree firmly planted by streams of water, which yields its fruit in its season and its leaf does not wither; and in whatever he does, he prospers.
One of the things that I most appreciated from his funeral was the effect that it had upon me as I left. As we reflected upon the life of a godly man, we were all confronted with the most important things in life: living godly and passing on the faith to our children and their children. The life of a man that I have never met has helped to remind me of what are the most important things in my life. And how I need to be about the business of keeping those things forefront in my life. It's the sort of reminder that we all need. How easy is it for us to forget. Things come into our lives which cloud our focus on eternity. We have need to remember what is most important in this life.
As we come, once again, to our exposition 2 Peter, Peter will give us some things to remember. This morning, we will look at only two verses. There is enough in these two verses to keep us occupied the entire morning, especially as it draws us to the Lord's Supper, near the end of my message. Consider our text:
2 Peter 3:1-2
This is now, beloved, the second letter I am writing to you in which I am stirring up your sincere mind by way of reminder, that you should remember the words spoken beforehand by the holy prophets and the commandment of the Lord and Savior spoken by your apostles.
These words give for us Peter's purpose in writing his epistle. It's not that Peter gives us the main message of 2 Peter, which I have summarized by the short phrase, "Know and Grow." But, Peter gives us his driving motive behind penning this letter. His purpose was one of reminding his readers. You can see that there at the end of verse 1, "I am stirring up your sincere mind by way or reminder." Fundamentally, Peter wasn't seeking to impart new information to his readers. Instead, he was bringing to remembrance those things that things that we already know. We need reminding.
Now, when you read these words, you can easily think that they are misplaced. Why does Peter tell us here, near the end of his epistle why he was writing these things? Doesn't it make more sense at the beginning of the letter? Wouldn't this read nicely.
2 Peter 1:1-2; 3:1-2
Simon Peter, a bond-servant and apostle of Jesus Christ, to those who have receive a faith of the same kind as ours, by the righteousness of our God and Savior, Jesus Christ: Grace and peace be multiplied to you in the knowledge of God and of Jesus our Lord. ... This is now, beloved, the second letter I am writing to you in which I am stirring up your sincere mind by way of reminder, that you should remember the words spoken beforehand by the holy prophets and the commandment of the Lord and Savior spoken by your apostles.
It would fit well there, wouldn't it? And yet, Peter waits until the third chapter to tell us this? Why? I don't have the answer to this question. Some have recognized how misplaced these words appear and have postulated that this is actually another letter that Peter wrote. Chapters 1-2 were Peter's second epistle. And chapter 3 constitutes Peter's third epistle (so they say). They contend that the ancient scribes then put both of these writings together to form a whole. I don't believe this at all. I believe that 2 Peter stands well as a whole.
It's not unusual for a writer to place the purpose for his writing toward the end of his writing. When Paul wrote 1 Timothy, he put his purpose statement right in the middle of the book: "I write so that you will know how one ought to conduct himself in the household of God" (1 Timothy 3:15). The gospel of John contains a purpose statement near the very end, in chapter 20. John writes, "These [things] have been written so that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name" (John 20:31). John's first epistle puts a purpose statement toward the end of the last chapter, "These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life" (1 John 5:13).
So, it's not so unusual that Peter would put his purpose so late in his letter. Nor, should it give us reason to doubt these words in any way. Rather, we ought to trust that when the Spirit of God inspired Peter, this is where he chose to insert his purpose behind writing his letter. And, the reason comes down to one word: remember. Look there again at the end of verse 1, "I am stirring up your sincere mind by way of reminder." It's not new stuff that Peter wanted them to know. Rather, it was the old stuff that Peter wanted them not to forget.
I love the way in which Peter is gentle with his readers. He doesn't say. "Hey, you bubbling fools! You are so forgetful. Do I have to tell you this again?" No. Peter doesn't do this. Instead, he gives a bit of encouragement within his exhortation. He says, "I know that you all have a pure and sincere mind, that earnestly want to seek and know the truth. I'm merely taking what you have and giving it what all of us need. We need a healthy dose of reminder. And so, that's what I'm giving to you all." This is what verses 1 and 2 are all about. They are Peter's attempt to remind his readers about the most central things, in this life. My message this morning is appropriately entitled, "Things to Remember." In these two verses, Peter gives us four things to remember. Here's my first point, ...
I pick this up from verse 1, where Peter speaks about a "second letter." Obviously, then, there was a "first letter." Peter is writing to these scattered believers, that they might remember the first letter that he wrote. The English Standard Version does a good job in bringing out the sense that Peter's speaking about his first epistle as well as his second epistle. Listen to that translation, "This is now the second letter that I am writing to you, beloved. In both of them I am stirring up your sincere mind by way of reminder."  Peter wants us to remember what he wrote in his first epistle. And he wants us to remember what he is writing in this epistle. But, with verse 1, Peter calls us back to remember his first epistle, which we call, "1 Peter."
We took a year preaching through 1 Peter, so I hope that those of you who were with us remember something about that epistle. I hope that four words come into your minds: "Suffer Now, Glory Later." This is how we chose to summarize the words of 2 Peter. Rather than proceed to our next point, I believe that it would be good for us to linger here for a bit reviewing Peter's first epistle. So, let's turn back now to 1 Peter and see where Peter talks about "Suffer Now, Glory Later." We can easily forget!
The first place this theme comes up is in chapter 1. In verse 3, he speaks about the glory that will come to us who believe in Christ. And then, in verse 6, Peter will tell us about the suffering now. Let's read 1 Peter 1:3-5, ...
1 Peter 1:3-5
Blessed be the God and Father of our Lord Jesus Christ, who according to His great mercy has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead, to obtain an inheritance which is imperishable and undefiled and will not fade away, reserved in heaven for you, who are protected by the power of God through faith for a salvation ready to be revealed in the last time.
This is all glory. Peter is telling us of our wonderful inheritance that awaits us. It is beyond whatever we have experienced here upon the earth. So great is the glory later, that it allows us to rejoice now, even through the trials and sufferings of this present age, which is exactly what verses 6 and 7 address.
1 Peter 1:6-7
In this you greatly rejoice, even though now for a little while, if necessary, you have been distressed by various trials, so that the proof of your faith, being more precious than gold which is perishable, even though tested by fire, may be found to result in praise and glory and honor at the revelation of Jesus Christ.
There it is: Suffer Now, Glory Later. Peter reminds us here that the glories to come are so wonderful, that it mades our suffering on earth worth it all.
You see "Suffer Now, Glory Later," come up again in chapter 2. Consider the following verses:
1 Peter 2:11-12
Beloved, I urge you as aliens and strangers to abstain from fleshly lusts which wage war against the soul. Keep your behavior excellent among the Gentiles, so that in the thing in which they slander you as evildoers, they may because of your good deeds, as they observe them, glorify God in the day of visitation."
In these verses, Peter addresses the issue of suffering. Suffering comes from sin (verse 11). Suffering comes from the ungodly (verse 12). And yet, what is it that will give you the ability to suffer rightly? It's the glory that comes later. Verse 11 points out that our battle with the flesh comes because we are from another world and it is toward that world that we look to live now. Peter calls us "aliens" and "strangers." That is, this world isn't our home. We are living for another. We are living for the glory that is to come. In verse 12, Peter tells us how to deal with the suffering that comes from the hands of others. We should walk in our good deeds today, so that they may give glory to God when He returns. There it is: Suffer Now, Glory Later.
Chapters 2 and 3 are filled with thoughts about suffering. We may suffer as citizens of an ungodly government (2:13-17). Some may be suffering as a submissive worker to an unruly master (2:18-20). Some women may be suffering in the midst of a difficult marriage with an unbelieving husband (3:1-6). And yet, through all this suffering, Peter calls us to continue to walk righteously through our sufferings, even calling us to remember the life of Christ.
1 Peter 2:21-23
For you have been called for this purpose, since Christ also suffered for you, leaving you an example for you to follow in His steps, "Who committed no sin, nor was any deceit found in His mouth"; and while being reviled, He did not revile in return; while suffering, He uttered no threats, but kept entrusting Himself to Him who judges righteously."
His suffering was great. His enduring through the suffering was amazing as well. And yet, how did Jesus do it? The end of verse 23 tells us. "He kept entrusting Himself to Him who judges righteously." In the end, all will be well, because we have a sovereign Lord who will insure that we will enjoy the glory that is to come. For the sake of time, let's consider one last verse in 1 Peter, where we see Peter's main point come to us clearly.
1 Peter 5:10
After you have suffered for a little while, the God of all grace, who called you to His eternal glory in Christ, will Himself perfect, confirm, strengthen and establish you.
This verse is great, because it contains the words, "suffer" and "glory" in the same verse. Peter is looking ahead to the time when we will enjoy the eternal glory with Christ. He's looking forward to the time when we will be perfect. But, until that time, there is suffering today. And Peter says that our suffering now is "for a little while." What makes it a little while? It's the glory at the end that makes it a little while. Seventy years of suffering here upon the earth may indeed seem like a long time. But, compared with eternity, it is merely a drop in the bucket.
When we've been there ten thousand years, bright shining as the
We've no less days to sing God's praise, than when we'd first begun.
So, let's (1) Remember the first epistle (verse 1). Let's remember that we are called to suffer here upon the earth. Let's remember to trust the Lord for the glory that is to come. Let's remember, using the words of Paul, "The sufferings of this present time are not worthy to be compared with the glory that is to be revealed to us" (Rom. 8:17). But, Peter doesn't merely call us to remember his first epistle. He also calls us to ...
Again, this is what Peter says in 2 Peter, chapter 3, verse 1, "This is now, beloved, the second letter I am writing to you in which I am stirring up your sincere mind by way of reminder."
Fundamentally, 2 Peter is a book of reminder. There's nothing new in 2 Peter that he wasn't convinced that his readers didn't already know. So, Peter says at this point, "I have been writing to remind you of the important things about life and eternity." And so, just as we spent some time reflecting upon 1 Peter, it would be good for us to spend a few moments here this morning reflecting back upon all that Peter has told us in 2 Peter. He is writing to remind us. So, let's be reminded!
Now, when you think of 2 Peter, there are three words that I hope you remember: "Know and Grow." This is how we have described the theme of 2 Peter. Peter has been calling us to know Christ and to grow in Him. One of the first things that you need to know is found in these words near the beginning of chapter 1, "His divine power has granted to us everything pertaining to life and godliness, through the true knowledge of Him who called us by His own glory and excellence" (2 Peter 3:1).
This verse tells us that we have all that we need to grow in Christ. We don't need another teaching. We don't need another experience. We don't need another friend. We don't need another revelation. We have it all in Christ. Peter's purpose in writing these things is to remind us of this most crucial fact about our spiritual lives. We have everything that we need to grow in Christ. We need to know this. We need to be reminded of this, because we can so easily forget. We have a world pulling us otherwise.
This was brought home to me this week as I was out and about on my day off. This past Monday found me in Lube Pro's having the oil changed in my van. As I was sitting there in the waiting room, I was reading a book by Steve Farrar entitled, "Finishing Strong." Another man noticed the title of the book and engaged me in conversation about the book. He said, "'Finishing Strong.' That sounds like a good book. Are you a part of a men's group?" I said, "No. I'm just reading this on my own." Then, he asked, "Does the book merely focus on being a father?" I said, "A little bit. Mostly, though, it has to do with living your life for Christ until the end." And then, I read a quote from a portion of the book that I had just read to give him an idea of the book.
The quote that I read to this man dealt with someone who studied various men in the Bible and how they finished their lives. Some finished poorly. Others finished so-so. And others finished well, meaning that they were "walking with God personally at the end of their lives. They were strong in their faith and close to the Lord."  I explained how the call of the book is to be like these men. Then, he said, "Do you know what the secret to finishing well is?" I said, "What do you think?" He said, "I think that there is one key to finishing well." At this point, my mind was perked up to listen to what he had to say. I was thinking that perhaps the Lord would use this man to communicate something crucial that I need to hear to help me finish well. He said, "The key to finishing well is miracles." Then he quoted a study of someone that noticed how those who experienced miracles stay strong in their lives and press others to be strong as well. I gently disagreed with him, using the example of those who came out of Egypt, having seen the miracles of the plagues. And yet, they grumbled and complained soon after leaving Egypt. And they hardly continued well to the end. But, this man wouldn't hear it. He said, "No. It's miracles that keep us strong. Our God is a miracle working God."
I'm here to tell you this morning that if you are looking for miracles to help you in your spiritual life, you have missed Peter's point. Peter says, "You don't need those things out there. You have everything that you need in Christ. So, trust in Him."
After I came home from my errand, I was talking with my oldest daughter. I had given her the assignment to read a book during Christmas break written by John Piper entitled, "The Roots of Endurance," which tells the stories of John Newton, Charles Simeon and William Wilberforce. After she read it, I had her write a simple, one-page paper for me entitled, "What I learned from The Roots of Endurance." Listen to what she wrote in her final paragraph. "What these three British men all had in common was that they all had incredible endurance and patience. They all persevered even through the toughest of trials and temptations. At the root of their endurance for the most part, seemed to be their devotion to spending time in the Bible and in prayer every day. If we can learn from these men to keep Christ at the center of all we do, think, and say, perhaps we will have 'Invincible perseverance' like John Newton, Charles Simeon, and William Wilberforce."
That's it! That's 2 Peter! John Newton and Charles Simeon and William Wilberforce could endure, because they kept reminding themselves that in Christ they have all that they need. They kept believing the message. They kept applying the message. They kept on persevering. Everything that these men had in Christ, we have as well. We have everything that we need, so let's know this and grow in grace.
If you are trusting in Christ for your salvation, then you have everything that you need to grow. He has given us faith (verse 1). He has given us grace and peace (verse 2). He has given us promises (verse 4). In short, He has given us everything (verse 3)! And so, the question becomes, "Are you growing?" This is the issue that Peter addresses, beginning in verse 5, "Now for this very reason also.." For what reason? Because God has given to us everything that we need to grow godly in Christ Jesus. "[Because we have been given everything in Christ], ...applying all diligence, in your faith supply moral excellence, and in your moral excellence, knowledge, and in your knowledge, self-control, and in your self-control, perseverance, and in your perseverance, godliness, and in your godliness, brotherly kindness, and in your brotherly kindness, love" (2 Peter 1:5-7).
Peter here is describing a growth in our lives that comes through faith in Him. As we believe in Him and trust in Him, we will see a pattern of growth in our lives. We will grow in moral excellence. We will grow in knowledge. We will grow in self-control. We will grow in perseverance. We will grow in godliness. We will grow in brotherly kindness. We will grow in love. Though we have been given everything in Christ that we need, we don't merely sit back and do nothing. On the contrary, we "apply all diligence" in our faith to apply our faith in these ways.
The results are clear. They come in verses 8 and 9, "For if these qualities are yours and are increasing, they render you neither useless nor unfruitful in the true knowledge of our Lord Jesus Christ. For he who lacks these qualities is blind or short-sighted, having forgotten his purification from his former sins" (2 Peter 1:8-9). If you are growing, you will be useful to the kingdom. If you are not growing, you are blind and forgetful. This is the message of 2 Peter.
Peter will never tire of reminding his readers that this is so. He wrote, "Therefore, I will always be ready to remind you of these things, even though you already know them, and have been established in the truth which is present with you. I consider it right, as long as I am in this earthly dwelling, to stir you up by way of reminder, knowing that the laying aside of my earthly dwelling is imminent, as also our Lord Jesus Christ has made clear to me. 15 And I will also be diligent that at any time after my departure you will be able to call these things to mind." What Peter said in chapter 1 is the same thing that he said in chapter 3. You need reminding. I'll always be willing to remind you. It's the burden of my message this morning. If Peter repeated himself twice, it's good for us to spend some time dwelling upon it as well. The priority that Peter has placed upon remembering what Peter has written is the very thing that has compelled me to go through only two verses today. 
As Peter continues his epistle in verse 16, his point remains the same. The Scriptures are sufficient for us. The apostles didn't follow fabricated fairy tale (verse 16). Rather, they were eyewitnesses of the majesty of Christ (verse 17). They were also earwitnesses of the Father's approval of the Son (verse 18). But, the prophetic word that we have is even more sure than such an experience, even if it was a miracle.
In chapter 2, Peter described the error of the false prophets. They professed a faith, but they weren't growing in their faith. Instead, they "denied the Master who bought them" (verse 1). And, they became entangled again in the defilements of the world, that they had once escaped from (verse 20). They turned away "from the holy commandment handed on to them" (verse 21). Fundamentally, their problem was that they didn't grow. They didn't "grow in the grace and knowledge of our Lord and Savior Jesus Christ," as Peter points out in verse 18. That's Peter's message. Know and grow.
Let's proceed onto my third point this morning. It is found in verse 2. Peter tells us to:
Peter writes in the first half of verse 2, "that you should remember the words spoken beforehand by the holy prophets." Peter says, "Remember the words of Isaiah. Remember the words of Jeremiah. Remember the words of Ezekiel and Daniel. Remember what the others, like Joel, Amos, Hosea, and Obadiah had told us beforehand."
That's pretty broad-sweeping, isn't it. You may hear this, and you say, "That's a lot to remember. Steve, are you going to review for us all that the prophets have spoken?" No. But, I do want to review a bit of what Peter quotes from the prophets. Because, if there is anything that Peter means by these words, "remember the words spoken beforehand by the holy prophets," at very least, he means the words that he has quoted in his epistles.
In 2 Peter, Peter mentioned very little about the prophets. Near the end of chapter 1, he spoke about them, telling us how it was that they wrote. Verses 20 and 21 read this way, "But know this first of all, that no prophecy of Scripture is a matter of one's own interpretation, for no prophecy was ever made by an act of human will, but men moved by the Holy Spirit spoke from God. If they spoke from God, they are worthy of our hearing. They are worthy of our remembering." Beyond that, 2 Peter gives little reference to the writings of the prophets. But, 1 Peter is a different story. When you read 1 Peter, you can't help but to see how often Peter quoted the prophets.
Back in 1 Peter, Peter mentions the struggle of the prophets with these words, "As to this salvation, the prophets who prophesied of the grace that [would come] to you made careful search and inquiry, seeking to know what person or time the Spirit of Christ within them was indicating as He predicted the sufferings of Christ and the glories to follow" (1 Peter 1:10-11). Here, Peter describes the searches and inquiries of the prophets. They wrote better than they knew, because, the Holy Spirit was moving them as the wrote. And they studied their own writings to try to understand who the Christ would be and when the Christ would come. They knew that the Christ would suffer. And, they knew that the Christ would experience glories later. "Seeking to know what person or time the Spirit of Christ within them was indicating as he predicted the sufferings of Christ and the glories to follow."
As we reflect upon the words of the prophets that were spoken beforehand, Peter would call us to remember the life of Christ. Jesus lived a difficult life. He suffered and died. And yet, His sufferings was the path to His glory. And His entrance to glory is our entrance to glory as well. The writer to the Hebrews says that Jesus "entered [heaven] as a forerunner for us" (Heb. 6:20). He has gone before us and blazed the trail for us. We follow Him by faith. But, that's not the only time that Peter mentions the prophets, who spoke before Christ came. Over in chapter 2, Peter mentions a few more.
Let's begin our survey of 1 Peter 2 in verse 6, "Behold, I lay in Zion, a choice stone, a precious corner stone, and he who believes in Him will not be disappointed." This quote comes from Isaiah 28:16. Isaiah is anticipating the time of the Messiah, when righteousness will again prevail. The glories of this time is that the one who believe in Christ will not be disappointed. The Messiah and all of His benefits become ours by faith in Him.
Peter continues to quote from the Old Testament in verse 7, "The stone which the builders rejected, this became the very cornerstone." Now, technically, this verse isn't from the prophets. It is from the Psalms: Psalm 118:22. But, it was spoken long before Christ came. And it directs us to anticipate the coming of the Messiah. He would be "the stone that the builders rejected" (verse 22a). This refers to the Jews who refused to receive their Messiah. Instead, they crucified Him. And the marvelous turn of events came next. "This became the very cornerstone" (verse 22b). It's good for us to remember that the cutting off of the Messiah was no accident. It didn't catch God by surprise. Rather, it was all in God's plan. It was all in accordance with "the words spoken beforehand by the holy prophets" (verse 2).
Verse 8 is another quote of the prophets, "A stone of stumbling and a rock of offense." This comes from Isaiah 8:14. This verse speaks about how people come to hate the LORD. Peter applies it to the Messiah. When He comes, people will hate Him. They will stumble over Him. And when you see that, don't be discouraged. Remember what the prophets spoke beforehand.
Peter continues to quote from the Old Testament prophets in verses 9 and 10. He throws together a bunch of terms used in the Old Testament to describe Israel. He pulls from Exodus, Deuteronomy, Isaiah, Malachi, and probably others. You are "a chosen race, a royal priesthood, a holy nation, a people for God's own possession" (verse 9). These phrases are used of the people of Israel. And yet, Peter applies them to us. Everything that God was for the Jews, He is now for us! Remember these things! Remember the great blessings that you have in Christ.
Peter continues in verse 10 with some words from Hosea. "For you once were not a people, but now you are the people of God; you had not received mercy, but now you have received mercy" (Hosea 1:10; 2:23). The is the gospel! We once walked in darkness, but now we walk in the light. God's wrath was once against us, but now God's kindness is toward us. Or, to use Hosea's words, "I will say to those were not My people, 'You are My people!'" It all took place in Christ. The prophets had spoken of it beforehand. So remember these things.
Let's look at one last section of Peter's epistle where he quotes from the prophets. It comes in chapter 2, verse 22, "Who committed no sin, nor was any deceit found in his mouth." This is a direct quote from Isaiah 53:9, describing the suffering servant who would come and bear the sins of many. Verses 23-25, though they aren't direct quotes, definitely allude to the truths found in Isaiah 53. The following table will help to show the correlation.
1 Peter 2 Isaiah 53 1 Peter 2:23 - and while being reviled, He did not revile in return; while suffering, He uttered no threats, but kept entrusting [Himself] to Him who judges righteously. Isaiah 53:7 - He was oppressed and He was afflicted, Yet He did not open His mouth; Like a lamb that is led to slaughter, And like a sheep that is silent before its shearers, So He did not open His mouth. 1 Peter 2:24 - and He Himself bore our sins in His body on the cross, that we might die to sin and live to righteousness; for by His wounds you were healed. Isaia 53:4 - Surely our griefs He Himself bore, and our sorrows He carried. 1 Peter 2:25 For you were continually straying like sheep, but now you have returned to the Shepherd and Guardian of your souls. Isaiah 53:6 - All of us like sheep have gone astray, each of us has turned to his own way; but the LORD has caused the iniquity of us all to fall on Him.
Surely, Peter had Isaiah 53 in mind when he told us to "remember the words spoken before hand by the holy prophets." When Peter quotes the prophets, most often, they focus upon the coming of the Messiah. This is what we must remember. The prophets prophesied that the Messiah would come, in whom we could believe, and not be disappointed (2:6). Who was rejected by men, but became the very cornerstone (2:7). Who many would continue to stumble over to their own doom (2:8). And when the Messiah came, He transformed us from those who were not people to those who are now His people (2:10). And how did He do it? By becoming our sin-bearing substitute upon the cross. That's why we gather this morning, not because we are righteous. But, because He is righteous.
Things to Remember: (1) Remember the first epistle (verse 1); (2) Remember the second epistle (verse 1); (3) Remember the words of the prophets (verse 2a); and now, ...
Peter writes at the end of verse 2, "and the commandment of the Lord and Savior spoken by your apostles." It is very difficult here to know exactly what Peter is referring to in these words. Some have taken it to mean the gospel of Christ, whereby he calls men to repentance and faith in Him. Some looked forward (to verse 3 and following) and say that the commandment has to do with the second coming of Christ. Some look backwards to chapter 2 and say that it relates to Christ's commands to avoid the false teachers. Still yet another interpretation might be to bring to mind Christ's words when he said, "A new commandment I give to you, that you love one another" (John 13:34).
I think that it is impossible to know for sure what Peter meant by this phrase. Certainly, He called us to repentance and faith. Mark 1:15 records the words of Jesus as he came into Galilee preaching the gospel of God. He said, "The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel" (Mark 1:15). This view has credibility because the only other time that Peter speaks about the "commandment" was in 2:21, when Peter says that the false teachers "turn away from the holy commandment handed on to them." They are turning from the gospel.
Certainly, Jesus spoke about His second coming. He said, "Just as the lightning comes from the east and flashes even to the west, so will the coming of the Son of Man be. ... Be on the alert, for you do not know which day your Lord is coming" (Matthew 24:27, 42). The strength of this view is verse 3, when Peter say, "Know this first of all, ..." that Jesus will come again. (And next week, we will look deeply into the second coming of Jesus. We must never forget that Jesus will return again, just as He has said).
Concerning the third possibility, Jesus spoke against false teachers. He said, "Beware of the false prophets, who come to you in sheep's clothing, but inwardly are ravenous wolves. You will know them by their fruits" (Matthew 7:15-16). This view gains strength when you think about the context of this letter. Peter has just finished denouncing the false teachers for an entire chapter, just as Jesus had done in His ministry as well.
Finally, Jesus instructed us to love. When Jesus was asked what the greatest commandment is, He elevated the command to love. Jesus said, "'You shall love the Lord your God with all your heart, and with all your soul, and with all your mind.' This is the great and foremost commandment. The second is like it, 'You shall love your neighbor as yourself.' On these two commandments depend the whole Law and the Prophets" (Matt. 22:37-40).
To pick and choose any one of these interpretations is very difficult (if not impossible). Perhaps Peter even had all of these in mind, "Remember what Jesus told us!" In some way, however, Peter calls us to remember the words of Christ. Take seriously the gospel accounts. Take seriously what the apostles said about Jesus. Remember His words. Follow His words. Obey His words. 
There is no better way to remember the words of Jesus than to celebrate the Lord's Supper. It is there that Christ told us to "Remember Him."
This sermon was delivered to Rock Valley Bible Church on
January 25, 2009 by Steve Brandon.
For more information see www.rvbc.cc.
 This doesn't come out so clearly in the New American Standard translation of this verse: "This is now, beloved, the second letter I am writing to you in which I am stirring up your sincere mind by way of reminder." The relative pronoun, "which" is a plural pronoun. This means that Peter was referring to two (or more) things when he spoke about stirring up their minds. A clarifying translation might read this way, "This is now, beloved, the second letter I am writing to you in both of which letters I am stirring up your sincere mind by way of reminder."
 If you are interested in pursuing this, you might want to check out John Piper's book, "What Jesus Demands of the World." In this book, John Piper has gathered many of the commands of Jesus from the four Gospels. Each of these commands are examined and applied carefully. You can read the book online here: http://www.desiringgod.org/ResourceLibrary/OnlineBooks/ByTitle/1822_What_Jesus_Demands_from_the_World/.