In I Corinthians 5 & 6, Paul writes of this. He is rather strong in his insistence that anyone who is a sister or brother in Christ is a new and different person. He warns that no one who has taken on the name of Believer is capable of behaviors or thoughts which do not reflect the promise of Christ.
During this Lenten season, as we examine our lives and our response to God, it is appropriate for us to name the transgressions of which we are guilty. It is appropriate for us to acknowledge those things which grieve God. And, it is the perfect time to confess our wrong, repent, and begin to live or lives differently.