As Karen from Girded with Truth blog shared,
CONFESSION OF SIN. We know that this is absolutely necessary to salvation. Unless there be a true and hearty confession of our sins to God, we have no promise that we shall find mercy through the blood of the Redeemer. "Whosoever confesseth his sins and forsaketh them shall find mercy." But there is no promise in the Bible to the man who will not confess his sins. Yet, as upon every point of Scripture there is a liability of being deceived, so more especially in the matter of confession of sin. There be many who make a confession, and a confession before God, who notwithstanding, receive no blessing, because their confession has not in it certain marks which are required by God to prove it genuine and sincere, and which demonstrate it to be the work of the Holy Spirit.
~ C.H. Spurgeon
A heart that does not *really* agree with God that one's sin *is* sin, is still in rebellion toward God and is still married to his sin. This is nothing but phariseeism. Mouthing the words, but the heart is far from God, still standing in pride and self-righteousness.
Rom 10:9 because, if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved. 10 For with the heart one believes and is justified, and with the mouth one confesses and is saved.
1Jn 1:8 If we say we have no sin, we deceive ourselves, and the truth is not in us.
1Jn 1:9 If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
1Jn 1:10 If we say we have not sinned, we make him a liar, and his word is not in us.
Psa 51:3 For I know my transgressions, and my sin is ever before me. 4 Against you, you only, have I sinned and done what is evil in your sight, so that you may be justified in your words and blameless in your judgment.
“If the professed convert distinctly and deliberately declares that he knows the Lord’s will but does not mean to attend to it, you are not to pamper his presumption, but it is your duty to assure him that he is not saved. Do not suppose that the Gospel is magnified or God glorified by going to the worldlings and telling them that they may be saved at this moment by simply accepting Christ as their Savior, while they are wedded to their idols, and their hearts are still in love with sin. If I do so I tell them a lie, pervert the Gospel , insult Christ, and turn the grace of God into lasciviousness.”