Repentence and conversion is a LIFELONG process, day in, day out.
Conversion is conversion. God doesn’t need to act more than once to save us.
2 Corinthians 5:17 says the old creature has passed away once the new creature in Christ is born. There’s no sense in trying to reconvert something that Scripture says is already dead.
However, repentance is daily, sometimes even more often. Matthew 6:33 reminds us to “seek ye FIRST the Kingdom of God AND his righteousness” — in that order. Since God sees the heart (1 Samuel 16:7), repentance is very much a regular process. Psalm 51 is a beautiful example.