Centuries before Christ, the Psalmist said:
“If thou, Lord, shouldst mark iniquities… who shall stand? But there is forgiveness with Thee…” (Psa. 130:3,4).
It is doubtful whether the Psalmist understood the basis upon which a just God, through the ages, has so graciously forgiven sins, but this has since been revealed in the Epistles of Paul.
There we read: “God for Christ’s sake hath forgiven you” (Eph. 4:32). But this is only part of the truth, for God forgives sinners, not merely because Christ desires this, but because Christ paid for their sins and purchased their redemption. Thus Eph. 1:7 declares: “In [Christ] we have redemption, through His blood, the forgiveness of sins, according to the riches of His grace.”
Obviously such forgiveness can never be rescinded or revoked, for it is based upon the full and complete payment of our whole debt of sin by “the precious blood of Christ.”
Sad to say, many people do not feel they need forgiveness, for they have not seen themselves as they truly are in the sight of a holy God, but those who are conscious of their sins and are willing to say with the prodigal son: “I have sinned,” may experience the peace and joy of sins forgiven by faith in Christ who paid sin’s penalty for us. source