John 5:14
Afterward Jesus findeth him in the temple, and said unto him, Behold, thou art made whole: sin no more, lest a worse thing come unto thee.
This man can still confess his past sins to another as a way to build up a weak brother who feels some guilt about a past sin as well:
2 Peter 1:9
But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins.
Because the scripture is clear:
1 John 3:9 KJVS
[9] Whosoever is born of God doth not commit sin
1 John 3:9 NIV
No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God.
1 John 3:9 NLT
Those who have been born into God’s family do not make a practice of sinning, because God’s life is in them. So they can’t keep on sinning, because they are children of God.
1 John 3:9-10 The Message
People conceived and brought into life by God don’t make a practice of sin. How could they? God’s seed is deep within them, making them who they are. It’s not in the nature of the God-born to practice and parade sin. Here’s how you tell the difference between God’s children and the Devil’s children: The one who won’t practice righteous ways isn’t from God, nor is the one who won’t love brother or sister. A simple test.
Absolutely true, but this is the sin of separation we repented of before we were reconciled to God. When we are born again into God's family we are no longer separated from him so we are no longer sinners, but we can do things that displease him - some people call these sins, but they are different to the sin of separation. The original sin, in fact.
You have fallen for believing a different gospel.