Isaiah 43:25

Blotteth out. Isaiah clearly sets forth Christ as man’s Saviour from sin. It is He who forgives men their sins. Divine forgiveness is not merely a legal transaction that wipes from the record the sins of the past, but a transforming power that eradicates sin from the life. By blotting out transgression God transforms sinners into saints. He thus effectually brings an end to sin. The doctrine of atonement for sin is clearly set forth in the OT as well as in the NT.

Not remember thy sins. Compare Isa. 1:18; Micah 7:19. That is, once they are confessed, forsaken, and forgiven. God treats a repentant sinner as if he had never sinned (see Eze. 18:20, 21). Christ’s words to the woman taken in sin are for all: “Neither do I condemn thee: go, and sin no more” (John 8:11).