To repent is to ask forgiveness for your sins:
1 John 1:9 New American Standard Bible (NASB)
9 If we confess our sins, He is faithful and righteous, so that He will forgive us our sins and cleanse us from all unrighteousness.
If we confess our known sins, then he will also forgive us of the sins which we are not aware that we have commited as well.
However, this has to do with the person who has accepted Yeshua (Jesus) as their savior while they are still alive praying to G*d for forgiveness of their sin in order to restore their fellowship with G*d through the filling of the Holy Spirit.