Do often!

 1 John 1:9

9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.

We are forgiven but we still sin. When we sin it hurts our relationship with God thus we need to confess that sin so we can be cleansed before God! Do this often...confess your sin to God! He tells us to do so!

Tom