2 Peter 3:15

We should view the Lord’s tarrying as a manifestation of His longsuffering that leads people to repentance and salvation rather than as an indication that He is never coming (2 Peter 3:9).

"While God is waiting, He is both giving time for the unbeliever to be saved, and for the believer to be working out his salvation (cf. Philippians 2:12-13) in terms of progress in sanctification." [Note: Wheaton, p. 1258.]

Peter regarded Paul as a "dear brother" who was one with him in his allegiance to God and His Word. Perhaps Peter had Romans 2:4 in mind when he said Paul wrote the same thing he had just said.