"To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins." (Acts 26:18)
All too often we consider forgiveness a mysterious and spiritual transaction that, once accomplished, is a past event that has little to do with our subsequent lives.
It is certainly true that there is a historical point in our earthly lives where the forgiveness of Christ was granted--even though He was "slain from the foundation of the world" (Revelation 13:8).
Christ has subdued, cleansed, and forgotten our sins: "Who is a God like unto thee, that pardoneth iniquity?... he will subdue our iniquities; and thou wilt cast all their sins into the depths of the sea" (Micah 7:18-19). "I, even I, am he that blotteth out thy transgressions for mine own sake, and will not remember thy sins" (Isaiah 43:25). "I have blotted out, as a thick cloud, thy transgressions, and, as a cloud, thy sins" (Isaiah 44:22).
Christ has replaced our sins with His holiness: "Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new…. For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him" (2 Corinthians 5:17, 21).
Christ has given us victory over sin: Since all of the above (and more) is true and active in the lives of all believers, there should be an obvious exhilaration that enables us to confidently stand against whatever "fiery darts" the enemy may throw at us. We are clearly told that "sin shall not have dominion over |us|" (Romans 6:14). And since Jesus already dealt with the "offence" of sin on the cross, we can "reign in life" by Him (Romans 5:17). HMM III