The letter ends very appropriately with a doxology, or expression of praise. The first part (grow in the grace and knowledge of our Lord and Savior Jesus Christ) recalls previous parts of the letter: grace recalls 1.2; knowledge recalls 1.5 and 1.8; our Lord and Savior Jesus Christ recalls 1.1, 1.8, and 1.11. Grace of course originates from and is given by Jesus Christ; knowledge may also be taken as knowledge imparted by Jesus Christ, although it is much more likely that this refers to the deeper understanding of the believers as they continue to study and meditate on the Good News of Jesus Christ. Grow is significant; it emphasizes the fact that it is not enough to refrain from being carried away or from losing your firm footing. More important than not falling is making a steady progress in your faith. The verb here is a present imperative, giving the sense of continuous action, as in Good News Translation “continue to grow.” Another translation model for the first part of this verse is:
• “But you should continue to experience more and more of the love and mercy of our Lord and Savior Jesus Christ, and grow in your understanding of him.”

The concluding expression of praise is unusual in that it is addressed to Jesus Christ, whereas usually such praises are addressed to God. It should be noted, however, that in this letter God and Jesus Christ are given the same titles and attributes, such as “Savior” (1.1, 11; 2.20; 3.2, 15), “divine” (1.3, 4). Glory can be honor or greatness, but in the context of this doxology is better taken as “praise.” The day of eternity is also unique in the New Testament, where the usual expression would be “forever.” Perhaps this is a reference to the day of the Parousia, which is thought of as lasting forever. The actual phrase day of eternity occurs in Sirach 18.10: “Like a drop of water from the sea and a grain of sand, so are a few years among the days of eternity” (New Revised Standard Version).

For Amen see comments on Jude verse 25.

It has been noted by some scholars that this concluding verse of 2 Peter blends beautifully Greek, Jewish, and Christian ideas and expressions. It is therefore a fitting conclusion to the letter, which as we have seen uses Greek and Jewish ideas and transforms them into appropriate vehicles of the Christian message. In this way this letter presents Christians of later generations, even today, with a model of how the wealth of various cultures can be appropriated for the Christian faith without sacrificing or compromising its truths and its demands.

Quoted with permission from Arichea, Daniel C. and Nida, Eugene A. A Handbook on The Second Letter from Peter. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .