Grow in Grace and Knowledge

A Sermon on 2 Peter 3:18

By Dr. John M. Frame

Professor of Systematic Theology and Philosophy
Reformed Theological Seminary, Orlando, FL

This sermon is from the heart in a special way, because, after a lot of talking to God and searching his word, it is what I think we most need to hear, today. It isn't necessarily our greatest area of need, but among the subjects which I think I can handle profitably, this is the one that seems most to cry out for attention today.

That subject is the one which is summarized in the last verse of our text: "But grow in grace and knowledge of our Lord and Savior Jesus Christ. To him be glory both now and forever! Amen" (2 Pet. 3:18).

Christian growth, that's the subject; that's our need. Babies are cute and delightful in many ways. But if a person were to remain a baby for ten years, twenty years, something would be terribly wrong. We would find in that "baby" something pitiful, something grotesque.

Now, in a literal, physical sense there are no twenty-year-old babies. But there are twenty-year-olds, forty-, sixty-year-olds who often act like babies. And what do we say about them? That they are cute and delightful? Think of a grown man coming to church with a flower in his lapel that squirts water at you. You mutter, "Joe, why don't you grow up?!" After a while, Joe might find himself without any friends, because people like that are unpleasant, a real pain in the neck.

Immaturity is hard to tolerate. I'm afraid that God is similarly annoyed by some of us, for there is a lot of spiritual immaturity among Christians today in the church. This is not necessarily a bad thing — much of it results because God has blessed our evangelism. The church has many young Christians whom we expect to be immature. That's great, that's wonderful. But we've got to keep encouraging the young Christians to grow. And older Christians too, for we never outgrow the need to grow. We need to emphasize the basics of the gospel: salvation by the death and resurrection of Christ, by God's grace (his free gift), by faith (not by anything we can do to earn it). That is quite proper. But let nobody misunderstand: there is a lot more to learn in God's word beside these basics. And it's sad when someone who has been a Christian for a long time knows nothing else than the simple gospel.

And sometimes you get into a situation when you just have to grow up, and grow up fast. Someone attacks your faith, or gets to one of your children in college. You have to grow up fast. The little book of 2 Peter deals with this kind of emergency situation. Let's look at it together.

These are the apostle Peter's last written words to the church, and he seems to know that he is getting near the end of his life. In 1:12-15 he talks about departing from his body, going to be with the Lord. To hear of Peter's departure might not only have saddened the church, but also frightened it — for a crisis was coming, an emergency. In chapter 2, Peter says that the church will be invaded by false teachers. These are bad news: "They will secretly introduce destructive heresies, even denying the sovereign Lord who bought them — bringing swift destruction upon themselves. Many will follow their shameful ways and will bring the way of truth into disrepute. In their greed these teachers will exploit you with stories they have made up."

How will the church survive this attack? How will the Christians be able to tell right from wrong in an age of theological confusion so much like our own? Well, they can follow Peter! In 1:12 Peter says he will keep reminding them of the truth, and in 1:16-18 he points out that his teaching is reliable: "We did not follow cleverly invented stories when we told you about the power and coming of our Lord Jesus Christ, but we were eyewitnesses of his majesty" (2 Pet. 1:16). But someone says, "Wait a minute, Peter. You're not going to be here forever. You yourself have said that you're getting near the end of your life. Where do we go for guidance after you die?" Peter's answer: "Go to the Bible!" Verse 19: "And we have the word of the prophets (the Bible) — something more certain — and you will do well to pay attention to it, as to a light shining in a dark place, until the day dawns and the morning star rises in your hearts. Above all, you must understand that no prophecy of Scripture came about by the prophet's own interpretation. For prophecy never had its origin in the will of man, but men spoke from God as they were carried along by the Holy Spirit."

Now in chapter three, Peter gives them an example of the kind of debate they will have with false teachers. And he tells them how to use the Bible in that debate. He wants to stimulate the church to "wholesome thinking" (3:1) as they recall the teachings of the prophets and apostles, what we call the Old and New Testaments. Now, the false teachers will deny the second coming of Christ: "They will say, where is this ‘coming' he promised? Ever since our fathers died, everything goes on as it has been since the beginning of creation" (2 Pet. 3:4). That's an ancient heresy, but also a modern one. Lots of people today are saying exactly that. Oh, it sounds a little different. Today people say "There will never be a return of Christ or final judgment, because the world operates according to scientific laws or at least statistical regularities; and there is no scientific evidence that any cataclysmic judgment is in the works."

Can you refute that argument? Can you show what is wrong with it? If you can't, you need to grow! Look what Peter says: "But they deliberately forget that long ago by God's word the heavens existed and the earth was formed out of water and by water." Did you know that? Did you know that the world was made, not only by God, but by God's Word? That's important. Did you know that the world was formed out of water, and that the Word of God kept the water and the dry land apart? Peter goes on in verse 6, "By these waters also the world of that time was deluged and destroyed." Noah's flood. Verse 7: "By the same Word the present heavens and earth are reserved for fire, being kept for the day of judgment and destruction of ungodly men."

See what Peter is saying? He's saying that the most basic principle in the world is not scientific law, not statistical regularity, but the Word of God. The Word of God is what made the world in the first place. The Word is what brought the great past judgment of Noah's flood (the language almost suggests a de-creation). And the Word will bring the next judgment, by fire. The implication is, we'd better listen to God's Word, rather than to unbelieving science or philosophy.

Peter tells us that when we live by the Word of God, we learn a whole different way of thinking: "wholesome" thinking. Everything becomes different. This is a frequent theme in the Bible. Proverbs teaches us that the fear of the Lord is the beginning of wisdom, so that in a sense unbelievers have no wisdom at all. Paul in 1 Corinthians 1-2 says that the wisdom of God is sharply opposed to the wisdom of the world. Peter agrees. A Christian biology is radically different from a non-Christian biology. A Christian economics is radically different from a non-Christian economics.

A Christian philosophy is radically different from a non-Christian philosophy. We cannot simply accept the fashionable thinking of the world; we must think differently! Not only must we think differently, but we must act differently. Peter says, "Look, if there really is going to be a second coming of Christ and a final judgment, how should we then live? Everything in this world will be burnt up. How should that affect our priorities?" Verse 14: "So then, dear friends, since you are looking forward to this, make every effort to be found spotless, blameless, and at peace with him." The Christian life is radically different from the non-Christian life. As Paul says (and Peter mentions that the false teachers twist Paul's letters), "If any man be in Christ, he is a new creation! Old things are passed away, behold, all things are become new" (2 Cor. 5:17).

Peter's conclusion: "Therefore, dear friends, since you already know this, be on your guard so that you may not be carried away by the error of lawless men and fall from your secure position" (2 Pet. 3:17). Does Peter write that to us? To all of us, or just to the elders? To all of us, you bet. All of us must be prepared to guard ourselves and our families against the Jehovah's Witnesses, the Mormons, the liberal Methodists and Presbyterians. For that, most of us need to grow, and grow a lot.

So finally we get to our special text in verse 18: "Grow in the grace and knowledge of our Lord and Savior Jesus Christ." Grow in grace, grow in knowledge. The first phrase includes the second, I think. Growth in grace includes growth in knowledge. But let's look in general at growth in grace, then we'll get more specific and talk about growth in knowledge.

Grow in grace: All growth is by grace; it's God's gift. We must constantly ask him in prayer to make us grow. We need God's grace, not only when we first believe in Christ, but we need it again and again, to become the people God wants us to be. Are you as loving and kind as you wish you were? If not, you need to grow in grace. Are you hospitable? Do you open your home and share your belongings with others who are in need? If not, you need to grow in grace. Do you witness to the lost in some way? If not, you need to grow. Do you support the ministry of your church with your time and resources as you promised when you became a member? If not, you need to grow. Do you keep the Lord's Day holy, a special day for God and away from your own work and play? If not, you need to grow. Are you teaching your children, intensively, from the scriptures, giving them the knowledge they need to withstand false teaching? If not, you need to grow. Do you love to worship Jesus, so that you seek out opportunities to praise him? If not, you need to grow. Is the Lord Jesus the first priority in your life, so that to serve him you would count everything else as garbage? If not, you need to grow in grace.

Now the second phrase: The kind of growth in grace that Peter especially singles out here is a growth in the knowledge of our Lord Jesus Christ. For it is knowledge especially that we need to combat the false teaching that swamps our culture today. How much knowledge do you have? Don't be satisfied with the simple gospel; there is so much more! If you rest content knowing only the simple gospel, you'll be powerless against the ingenious philosophies of the modern world, and Satan will grab your children, because you haven't taught them. Think how much there is to learn in the Bible!

There's the doctrine of creation in Genesis 1. God made the whole heavens and earth out of nothing. Doesn't that blow your mind? And it's important in a lot of ways. You can't understand salvation very well without understanding creation. 2 Corinthians 4:6 reads, "God, who said, ‘Let light shine out of darkness,' made his light shine in our hearts to give us the light of the knowledge of the glory of God in the face of Jesus Christ." And Peter taught us that the de-creation of the world will be in many ways like its creation.

Then there's the doctrine of man as the image of God, in Genesis 1:26-28. Do you understand that? If not, you don't understand yourself the way God wants you to. And the doctrine of sin: do you know from what you are saved? Do you know how black your sin is in God's sight? When you learn that, you'll be more thankful for your salvation. You'll praise God more loudly and you'll witness more fervently.

There's the doctrine of the covenant. Do you know what a covenant is? That's the sort of thing that sometimes falls through the cracks. We have to work at understanding it, at making it a basic part of our thinking. The covenant is the basic nature of our relation with God. The covenant is the family of God. If you don't understand it, you don't understand the meaning of baptism, and you don't understand where your children fit into the church.

There's the doctrine of the person of Christ. Have you ever wrestled with the question of how Jesus could be truly God and truly man? If not, you're not ready to present the gospel to Jehovah's Witnesses. And the work of Christ: how can one man's death bear the punishment for someone else's sins? Your children might ask you that sometime.

And we can go on: regeneration, faith, repentance, justification, adoption, perseverance, glorification, the return of Christ and the judgment. Can you work your way through all the many confusing teachings in these areas you hear on t.v., read in books, and hear from time to time on your own doorstep? You need to. You see how sad it is when Christians know only the simple gospel, how ill-equipped they are.

God tells us we need to grow. He offers us his grace in Jesus Christ to change our lives and to enable our minds to understand. And he gives us the tools we need — his Word and the teaching ministry of the church — to communicate what we need to know. I'll end, as Peter does, by ascribing to Jesus the glory both now and forever, Amen! He is the one whom we seek to know, and he is the one who supplies the grace we need to grow.