An eternal unchanging law of the universe is revealed in Heb. 9:22. Without the shedding of blood there is no remission — that is, no forgiveness. Because human forgiveness simply remits a deserved penalty, men need the revelation that because of His holy character God can forgive men only on the basis of the full execution of the penalty. This is why the offering of a sacrifice for atonement was necessary in OT days, Lev. 4:35.
Christ shed His blood for the remission of sins, Matt. 26:28. All who trust in Him as the Lamb of God are forgiven all trespasses, past, present, and future, Col. 2:13; 1 John 2:12. They are forever delivered from all condemnation, John 3:18; 5:24. Forgiveness is sometimes thought of as the negative aspect of salvation, which also includes justification, Rom. 5:1, an inheritance, Acts 26:18, and much more.
When Christians fall into sin, fellowship with the Father is broken. The remedy is confession of the sin to God, 1 John 1:9. He freely forgives and restores. Failure to judge and forsake sin brings chastisement to a believer, 1 Cor. 11:31, 32. This family relationship is also in view in Mark 11:25, 26, where a forgiving spirit is required before the Father will forgive His children. A concise statement of this principle appears in Eph. 4:32. Believers are to forgive one another, even as God for Christ’s sake has forgiven them.
William Evans, The Great Doctrines of the Bible, (Chicago: Bible Institute Colportage Assoc., 1912), WORDsearch CROSS e-book, Under: “Forgiveness”.