“The Lord does not delay His promise, as some understand delay, but is patient with you, not wanting any to perish but all to come to repentance.”
Perhaps Peter means we are impatient for the Lord’s return; and fret over its delay in an incorrect way. Rather than being ready for Christ and helping others ready themselves for His return, we stamp our feet and wring our hands, wondering why He tarries. Some of us even set the time for His return, announcing that on such and such a date, Christ will come for His own. We don’t seem to care that everyone else will be doomed.
On top of this impatience and imprudence, we forget God is patient. We ignore that God is kind; that He does “not want any to perish but all to come to repentance.”