Short answer
– The letter itself names its author as “Simeon (Simon) Peter, a servant and apostle of Jesus Christ” (2 Peter 1:1). From a typical evangelical perspective the most likely author is the apostle Peter (the same Simon Peter who followed Jesus), and the letter’s authority rests on that apostolic authorship.

Why evangelicals commonly affirm Petrine authorship
– The letter’s own claim: it opens with Peter’s name and repeatedly appeals to eyewitness apostolic testimony (cf. 2 Pet. 1:16–18). Evangelicals treat those internal claims seriously unless there is strong contrary evidence.
– Eyewitness emphasis: 2 Peter repeatedly appeals to Peter’s experience with Jesus (the transfiguration, etc.), which fits an apostle’s self-understanding.
– Early church reception: although 2 Peter had a slower reception than some New Testament books, it was accepted into the canon by the church and is quoted or attested by early Christian writers; evangelicals see that as consistent with apostolic origin and early use.
– Theological and pastoral fit: the teaching in the letter (warnings against false teachers, stress on moral growth, and reliance on apostolic testimony) fits what would be expected of Peter’s pastoral concern for the churches.

Common objections and evangelical responses
– Objection: style and vocabulary differ markedly from 1 Peter. Response: evangelicals appeal to plausible explanations—different occasions and audiences, different subject matter, different mood (hortatory vs. epistolary), possible use of an amanuensis/secretary, or natural variation in Peter’s Greek (he was a bilingual Galilean whose Greek might vary). These explanations can account for stylistic differences without denying Petrine authorship.
– Objection: apparent literary dependence between 2 Peter and Jude (they share material). Response: evangelicals propose several possibilities: Peter used Jude (who was a brother of James), they both used a common source, or there was normal interletter citation in the early church. None of these options necessarily implies forgery.
– Objection: some date 2 Peter late (after Peter’s death), which would imply pseudonymity. Response: many evangelicals favor an earlier date (before Peter’s martyrdom under Nero, ca. AD 64–68), consistent with apostolic authorship; others who accept a later date often still emphasize the letter’s apostolic authority or argue for different interpretive solutions. Evangelicals generally reject deliberate pseudonymous authorship because it conflicts with New Testament standards for truthfulness and apostolic integrity.

How authorship matters theologically
– If written by Peter, the letter carries apostolic authority, strengthening its standing as part of the New Testament canon. For evangelicals who affirm biblical inspiration and authority, Petrine authorship undergirds the letter’s doctrinal and ethical weight.
– Practically, 2 Peter 1:4 (“partakers of the divine nature… escape corruption”) is read as apostolic instruction about sanctification grounded in God’s promises and power—consistent with the teaching of the other apostles.

If you want to go deeper
– I can summarize the main internal arguments (phrases and parallels within the letter) and the main external arguments from the early church fathers, or show how prominent evangelical commentaries treat the authorship question. Which of those would you prefer?