In 1 Timothy 1:15 Paul, writing as an apostle, to other Christians, calls himself the foremost of sinners in the present tense. You also didn't address 1 John 1:8, another post-conversion verse. From John the apostle, to other Christians. In Colossians 3:5 Paul commands believers to put to death what is earthly in you, which only makes sense if something earthly remains to be put to death. Sanctification is a lifelong process. Luke 18 is a warning. The Pharisee stopped praying the sinner's prayer because he thinks his identity has moved past it. It is not a stage you graduate from.