"If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth;"
1 John 1:6
If we truly have a relationship with Christ, then we will hate sin. This doesn't mean we won't sin. As long as we're here on earth it's for certain we will. But when we do, we should feel disappointment in ourselves and a desire to talk to God about it; to confess our sin and ask for His forgiveness. Such honesty is pleasing to God and He is more than willing to forgive us (1 John 1:9). Corrie Ten Boom said, "The blood of Jesus never cleansed an excuse."