The New Testament has much to say about the importance of knowledge for the Christian (Philippians 1:9; etc.). But what exactly is “knowledge” – is it understanding of important Christian doctrines or of the Christian way of life? The second epistle of the apostle Peter answers this question for us.
Peter begins his letter with the greeting: “Grace and peace be yours in abundance through the knowledge of God and of Jesus our Lord” (2 Peter 1:1), and if we did not notice what the knowledge is that Peter had in mind, he continues by saying that through his divine power God “has given us everything we need for a godly life through our knowledge of him who called us” (2 Peter 1:2–3). In the same way, Peter closes his letter with the command: “grow in the grace and knowledge of our Lord and Savior Jesus Christ” (2 Peter 3:18).
So Peter bookends everything he has to say in his second letter to fellow believers by stressing the importance of knowledge, and between these two statements Peter repeatedly returns to the same point (2 Peter 2:20; etc.). In every instance he makes it clear that the knowledge we need and need to seek is not simply doctrinal or practical Christian knowledge, but knowledge about God and Jesus Christ.
What Peter means by this is that Christian growth is not somehow guaranteed by what we do. It does not automatically come as a result of attending church enough – any more than just sitting in a gym is going to make us stronger, or of studying our Bibles enough – any more than reading a book about cars is going to make us auto mechanics. It is only as we come to know God and Jesus Christ through a relationship with them that we really grow toward them and become more like them.
When Peter writes “Grow in the grace and knowledge of our Lord and Savior Jesus Christ” (2 Peter 3:18), the two are related – we grow in the grace of Christ by growing in the knowledge of Christ. This affects every aspect of our Christian lives. The more we grow in that kind of knowledge the more we grow in obedience and love (1 John 4:7–8). As Peter says: “For this very reason, make every effort to add to your faith virtue; and to virtue, knowledge … For if you possess these qualities and continue to grow in them, they will keep you from being ineffective and unproductive in your knowledge of our Lord Jesus Christ” (2 Peter1:5,8).
It is not just Peter who tells us these things. The Old Testament tells us that God desires “the knowledge of God rather than burnt offerings” (Hosea 6:6), and Jesus himself prayed “this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent” (John 17:3). The apostle Paul frequently refers to this truth, telling the believers at Ephesus, for example: “I pray that the God of our Lord Jesus Christ, the glorious Father, would give you the Spirit of wisdom and revelation in the knowledge of him” (Ephesians 1:17 CSB), and those in Corinth “We continually ask God to fill you with the knowledge of his will through all the wisdom and understanding that the Spirit gives, so that you may live a life worthy of the Lord and please him in every way: bearing fruit in every good work, growing in the knowledge of God” (Colossians 1:9–10).
As Christians we need to produce the fruit of good works in our lives (Matthew 7:16–20; Ephesians 2:10; Titus 2:7; Colossians 1:10; etc.), but we must never forget that the growth of those fruits comes not from study alone or from some kind of religious exercise, but from becoming more like God through the work of the Holy Spirit as we grow in our knowledge of the Father and the Son of God.
