The Promise of His Coming (2 Peter 3:3-7).
‘Knowing this first, that in the last days mockers will come with mockery, walking after their own lusts,'
Compare here Jude 1:17-18, ‘remember the words which have been spoken before by the Apostles of our Lord Jesus Christ, how that they said to you, “In the last time there will be mockers, walking after their own ungodly desires”.' Both agree that it was an emphasis of the Apostles that ‘mockers' would arise (see 1 Timothy 4:1-3; 2 Timothy 3:1-9; 1 John 2:18-20; 1 John 2:22-23; 1 John 4:1-6). And the reason that they mock is because they are following their own evil desires. They are caught up in sin. Thus they mock what they see as not offering them what they want. They do not want their adherents to be disturbed by the thought of the actual coming in history of the Christ. They want to live their lives in the flesh as though He had not come, while enjoying what they see as heavenly experiences in their spirits. It is a salutary warning that those who followed the desires of the world did not like to think of either His coming or His second coming.
Note how Peter clearly considers that he is already in ‘the last days', for he sees the mockers as already present. Compare Acts 2:17; 1Pe 1:20; 1 Peter 4:10; 1 Corinthians 10:11; Hebrews 1:1-2; Hebrews 9:26-28 where the same idea is found. To all the Apostles the last days had begun with the coming of Jesus and the days following Pentecost were continuing ‘the last days' prior to His return.
Note on ‘In the last days.'
If Peter has taken his ideas from Jude, which is a good possibility, then he has deliberately changed ep eschatou chronou (upon the last time) into ep eschatown town hemerown (upon the last of the last days). And we then have to ask why he has changed ‘time' to ‘days', especially as in 1 Peter 1:5 we have en kairow eschatow (in the last time), and in 1 Peter 1:20 we have ep eschatou town chronown (upon the last of the times).
It may partly have been because he had in mind Joel 2:28 as cited in Acts 2:17, although there we have en tais eschatais hemerais (in the last days). However, that rendering may have come from the Greek source of his citation. The alteration here may therefore be Peter's representation of the same idea (many years had passed since Acts 2).
On the other hand Hebrews 1:2 has ep eschatou town hemerown toutown, which is the closest to here, and he may have taken it from there. For we have seen how 1 and 2 Peter sometimes reflect a similar pattern of thought to Hebrews, and indeed Peter may well have read Hebrews. The slight difference from Hebrews may partly reflect the preference of his amanuensis.
However, probably the best reason for the change to ‘days' is that he was about to speak in 2 Peter 3:8 about ‘a day' being to the Lord ‘as a thousand years', and a thousand years as a day. That would indicate that he wanted it recognised that the mocking might well go on for a long time.
End of note.