There are always some who mistake what repentance is. Repentance (Gk. metanoia) is not forsaking sin. This is the consequence of repentance, not repentance itself. God repents frequently in Scripture (Genesis 6:6; Exodus 32:14; 1 Samuel 15:35; 2 Samuel 24:16; 1 Chronicles 21:15, etc.). Does He repent of sin? Obviously not. Repentance is simply changing one's mind about something, thinking differently on some point, taking a new course in what one believes about a particular matter. This change of mind may lead to regret, to sorrow, to confession of sin, to a determination to think and act differently but ought not to be confused with these things.
Can a born-again Christian repent? Well, if God can and does, certainly His children can and will, too. Changing one's mind about one's beliefs, about one's attitudes and living, is essential to growing as a disciple of Christ. And so we read in Scripture:
2 Corinthians 7:8-12
Revelation 2:5
Revelation 3:3
Revelation 3:19