The term (literally, "at + one + ment") has been applied since the earliest English translations of the Bible to the sacrificial ceremonies in the Hebrew temple on Yom Kippur (Day of Atonement). It has come to be applied universally to God's reconciling work accomplished by the death of Christ. This is supported by the treatment of Jesus' death in the epistle to the Hebrews as the fulfillment of the temple sacrifices. There is widespread agreement among contemporary theologians that God's reconciling work includes Christ's life as well as his death.
In the NT this work is described by an abundance of metaphors, some drawn from religious life (sacrifice and sanctification, Heb 9-10), some from legal life (justification, Rom 5), some from personal life (reconciliation and forgiveness, 2 Cor 5), and ransom and redemption from Satan (Mk 10:45). In his book Christus Victor, Gustaf Aulén identified three leading theories of atonement: 1) victory over Satan, which he regarded as the most adequate, the "classical" view; 2) sacrifice and satisfaction, the "Anselmian" view; 3) the "moral influence" theory, derived from Peter Abelard and used in much modern Protestant thought. The Episcopal theologian William Porcher DuBose emphasized an understanding of atonement as the fulfillment and intended end of humanity in union (at-one-ment) with God.