Universal (or unlimited) atonement is the view that Christ's work makes redemption possible for all but certain for none. According to this doctrine, whatever Christ accomplished on the cross, he accomplished for all alike those who are finally saved as well as those who are finally lost. This view is contrasted to the Reformed doctrine of limited (or definite) atonement.
This view of the atonement is advocated by Arminian/Methodist, Lutheran, and Roman Catholic theologians (among others). Though Lutherans and Catholics share a similar doctrine of the nature of the atonement with Reformed theology (that being vicarious substitution), they differ on its extent, whereas Arminians and Methodists generally accept an alternate theory of the nature of the atonement such as the moral government theory. In either case, the elect in such models are those who choose to avail themselves of God's gracious offer of salvation in Christ by their own free will, not a pre-determined group. Thus, these systems place a limit on the "efficacy" of the atonement rather than on its extent, as do Calvinists.
This doctrine should not be confused with Universalism which maintains that all mankind will be saved.
Historically, the Arminian Remonstrants raised this doctrine of "universal atonement" as a point of debate against the predestinarian view of the Belgic Confession, which in turn led to the Synod of Dort (1618-1619) where the doctrine was rejected. Nevertheless, this doctrine of the universal extent of the atonement became and remains prevalent outside of Calvinistic circles. Even some Calvinistic Christians, identifying themselves as Amyraldians or "four point Calvinists," hold to an unlimited atonement. In particular, Amyraldism teaches that God has provided Christ's atonement for "all alike," but seeing that none would believe on their own, he then elects those whom he will bring to faith in Christ, thereby preserving the Calvinist doctrine of "unconditional" election.