Repentance as it is referred to in the Bible only refers to asking God for forgiveness,it is strictly a spiritual act involving us and God.
Repentance is one of the most important teachings in the Christian faith because without it God will not forgive our sins as this verse indicates:
Acts 3:19 (New King James Version)
Repent therefore and be converted, that your sins may be blotted out, so that times of refreshing may come from the presence of the Lord.
This issue is both significant and extremely urgent because many in the "once saved always saved" camp are now telling their followers that they never need to repent for their sins.For that reason it is necessary for Christians to decide who they want to believe,a minister or Jesus.
Luke 13:3 (New King James Version)
I tell you, no; but unless you repent you will all likewise perish.
The bad news is that failure to change behavior after repentance is common but the good news is that God is forgiving,at least up to the point where He begins to regard repeated sin and repentance as hypocrisy.