1 John 1:8-9, If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, [God] is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
It could not be any clearer. We are all sinners. If we deny this, such as unbelievers and the heretic Joyce Meyer, we deceive ourselves and the truth is not in us. But if we confess our sins, God is faithful and righteous to forgive our sins and cleanse us from our unrighteousness. It matters not what the sin is. It could be murder, rape, molestation, being a bully, dishonouring one’s parent’s, whatever—if it is confessed by faith in genuine contrition, God is faithful and righteous to forgive you. To deny these are sins is a sin, for you make God a liar. Indeed, even to say these sins are unforgivable is a sin, for you make God a liar. Nothing is impossible for God (Luke 1:37), even forgiving the sins we label as unforgivable. For since God said He will forgive all our sins, He can and He will. To not believe this is to call God a liar, which is a grave sin.
The Lutheran Column 