Repentance is to change your mind with regards to the worldly way to obtain salvation. What is the worldly way to obtain salvation? The worldly way of salvation is to stop sinning and do more good works to be qualify for God's acceptance. But according to God, no sinner can enter heaven. That includes sinner who by their own definition has stopped sinning (in reality, no sinner can stop sinning in action or thought). A sinner who is able to sin less and do a lot of good works, is just a well behaved sinner. A sinner is still a sinner regardless whether he is sinning less and did a lot of good works. No amount of good works or committing less sin will change the status of a sinner into a saint. True repentance is to understand that a sinner cannot save himself because nobody can change their sinner status through good works or committing less sins. The only way to change the sinner status is to accept Jesus' payment for our sins and to be BORN AGAIN (made into a new creation).