Some have understood this sentence as referring to a prophecy made by Peter and the apostles regarding false prophets and apostasy in the last days.1 Alternatively he might simply be alluding to passages like Matthew 24:11 or Mark 13:22. Jesus himself also warned against false teachers (Matthew 7:15–23). Other New Testament letters give instructions as to how to differentiate between the true and the false (1 Thessalonians 5:20–22; 2 Thessalonians 2:2; 1 John 4:1–3). It was predicted that heretics would come in the last days (2 Peter 3:3–4). (Last days is a phrase used in Scripture to refer to the time between Christ’s ascension and his second coming. All Christian believers have lived and currently live in the time period known as the last days.
)Thus the heretics' presence in the church is evidence that the last days have come (2 Peter 3:5–7).
1 But false prophets also arose among the people, just as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Master who bought them, bringing upon themselves swift destruction.