Welcome to 2 Peter!
Below is helpful information I found in Fee and Stuarts Book, “How to Read the Bible Book by Book:“
Orienting Data for 2 Peter
Content: a “farewell speech” sent as a letter, urging Christian growth and perseverance in light of some false teachers who both deny the second coming of Christ and live boldly in sin
Author: the apostle Peter, although questioned both in the early church and by most New Testament scholars; possibly a disciple who wrote a kind of “testament of Peter” for the church
Date: ca. a.d. 64 (if by Peter); later if by a disciple
Recipients: an unknown but specific group of believers
Occasion: a desire to establish the readers in their own faith and godly living, while warning them of the false teachers and their way of life
Emphases: concern that God’s people grow in and exhibit godliness; the sure judgment on the false teachers for their ungodly living; the certainty of the Lord’s coming, despite the scoffing of the false teachers
Overview of 2 Peter
The letter is in four parts that focus on godly living in light of the certainty of the Lord’s coming, against the backdrop of those who deny the latter, with its concomitant judgments, and who thus live like pagans. Part 1 (1:3–11) is an exhortation to growth in godliness, thus confirming their “calling and election” (v. 10) so as to “receive a rich welcome into the eternal kingdom” (v. 11).
Part 2 (1:12–21) is Peter’s testament about the “coming of our Lord Jesus Christ” (v. 16), an event that both the transfiguration (vv. 16–18), which Peter witnessed, and the reliable word of prophecy (vv. 19–21) argue for.
All of this is set (in Part 3) in the context of the greed and licentiousness of the false teachers, whose condemnation is certain (2:1–22). The main thrust of this section is to reaffirm the certainty of divine judgment on those who reject God by rejecting holy living; thus several Old Testament examples are brought forward by way of illustration. You may want to read Jude 4–18alongside this passage, since it reflects similar concerns and uses some of the same examples from the Old Testament and Jewish apocalyptic. These teachers “promise freedom” but are themselves “slaves of depravity” (2 Pet 2:19), who would finally have been better off never having followed Christ than to have followed and then rejected him (vv. 20–22).
The false teaching itself is exposed and argued against in 3:1–18(Part 4). Against those who deny the second coming (vv. 3–4) is the certainty of God’s word, and thus the certainty of coming judgment, and a biblical view both of “time” and of God’s patience (vv. 5–10); the conclusion urges readiness, in obvious contrast to the recklessness of the false teachers (vv. 11–18).
Specific Advice for Reading 2 Peter
Watch for the two (interlocking) concerns that drive 2 Peter from beginning to end: (1) the false teachers as such and (2) their denial of the second coming of Christ. You will find the description of them in chapter 2 especially vivid. Besides their immorality (licentiousness, sexual immorality, disavowal of authority), note that they are especially scored for their greed (2:3, 14–15) and the exploitation of the unsuspecting and unstable (2:3, 14, 18–19). And the twin pictures of their rejection of Christ are especially graphic—a dog returning to its vomit, a washed sow returning to wallow in the mud (v. 22). Note also how those on the other side, who eagerly await the coming of our Lord, are exhorted to “holy and godly” living (3:11–12).
Regarding the certainty of the coming of Christ, which will include inevitable judgment on those who reject him by the way they live, be watching for the emphasis on the sure word of prophecy, both Old Testament and apostolic. This is the point of 1:16–18 and1:19–21, where the transfiguration of Christ itself was a prophetic foretaste of the future, and where true prophecy is completely reliable. The coming of the “false prophets” is also prophesied (2:1), while the final exhortation (ch. 3) begins by reminding the readers once more of the sure word of the “holy prophets” and the “apostles,” with emphasis on the reliability of God’s word—that the same word that brought the created world into being is preserving it for the day of judgment.