Repentance allows God's mercy to come forth because it recognizes that the sin committed was against God. It also bares contriteness of the heart and the desire to walk in the Spirit and not in the flesh so that particular sin will never be repeated.
I must not mix champage, whiskey, and gin. (Repeated fifty times to fill column.)
The Bible will keep you from sin, or sin will keep you from the Bible.
Dwight L. Moody