FAITHFUL AND JUST
Believers are told that God's forgiveness is always available to cleanse - completely:
"If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness," 1 John 1'9.
Where does unrighteousness come in relation to sin? 1 John 5'17 says that "All unrighteousness is sin, and there is sin not leading to death"
It would seem that unrighteousness is the kind of sin that Believers commit when they do something against the will of God.
Although it is not sinful it is not righteous, that is, right before God. Therefore, it "is not leading to death".
The faithfulness and justice of God assure Believers when they need to go to the Throne of Grace for spiritual cleansing.
There is no sin or unrighteous act that can bar a Believer from going to the Father for forgiveness in Jesus' name.
To emphasise the position, "... if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous," 1 John 2'1.
Although the devil himself might say otherwise, although he may try to deceive, he does not have the authority to stop a Believer.
God's mercy is always available and His grace is sufficient. Confess, repent, ask, and He will forgive.