The word atonement was first used by William Tyndale in his English translation of the Bible to signify the process of bringing humanity back into a state of oneness (at-one-ment) with God. In LDS teachings, atonement connotes both a process and an event. It describes the reconciliation between humanity and God made possible by the sacrifice, suffering, and death of Jesus Christ. The atonement makes it possible for humanity to overcome sin and death, and is described in LDS scripture as the “work and glory” of God.

For behold, this is my work and my glory—to bring to pass the immortality and eternal life of humanity.
Moses 1:39

Christian theologians have long debated how the atonement brings salvation to humanity and what the nature and extent of that salvation is. One of the earliest theories of atonement is often referred to as the Ransom theory, which claimed that God freed humanity from captivity by persuading Satan to accept the torture and death of Jesus in humanity’s place, causing Satan to overstep his rightful claim by punishing a sinless man. According to this theory, this overreach on Satan's part forced him to relinquish his claim on sinful humanity.

The Redeemer came and the deceiver was overcome. What did our Redeemer do to our Captor? In payment for us He set the trap, His Cross, with His blood for bait. Satan could indeed shed that blood; but he deserved not to drink it. By shedding the blood of One who was not his debtor, he was forced to release his debtors.
St. Augustine

Dissatisfaction with this theory led others to propose the atonement as punishment endured by Jesus in humanity’s place to satisfy the demands of justice, thus allowing God to fairly forgive sins. This view of atonement is called substitutionary atonement. Still others found this theory unsatisfactory, in part because it seemed unfair to punish a person for another’s sins, and because it can make God seem offended, harsh or judgmental.

Another theory hinted at by early Christian leaders and later by Peter Abelard, a medieval French theologian, was the moral influence theory, which proposed that Jesus lived and died to demonstrate God's love, so that humanity might be persuaded to follow his example and eventually be reconciled with God and one another.

And my Father sent me that I might be lifted up upon the cross; and after that I had been lifted up upon the cross, that I might draw all people unto me.
3 Nephi 27:14

Mormon teachings on the atonement share some aspects of all these theories of atonement. The prophet Amulek in the Book of Mormon points out that the law will not allow any person to be sacrificed for the sins of another, thus explaining the limitations of a conventional concept of substitution, and claiming that the atonement must therefore be “an infinite and eternal sacrifice” (Alma 34:10). Later on, the risen Christ proclaims to the Nephite civilization that he was “lifted up upon the cross” in order to “draw all people unto Him,” forshadowing the profound power of his example in persuading others to be reconciled to God. The apostle Paul taught that “we love him because he first loved us” (1 John 4:19).

Mormon theology emphasizes the necessity of human agency, proclaiming that “no power or influence can . . . be maintained by virtue of [authority], only by persuasion, . . . without compulsory means” (D&C 121:41, 46). LDS theology also teaches that humanity has a duty to take upon itself the name of Christ and participate with Him in extending salvation to others through humanitarian service, preaching the gospel, and doing vicarious work on behalf of the dead. Through this work, Christ's followers become “Saviors on Mount Zion” (Obadiah 1:21, D&C 103:9-10).

God's “work and glory” is “to bring to pass the immortality and eternal life of humanity” (Moses 1:39). These essential outcomes cannot be achieved without the voluntary participation of God's children. To the extent these outcomes have not yet been fully achieved, the atonement is still an ongoing process, and will not be complete until humanity is fully reconciled with one another and God in Christ. By taking Christ's name upon us and doing our best to follow his example and do what He would do if He were here among us, we experience the joy and privilege of participating in His atonement. The apostle Paul expresses this joy of participating in Christ's atonement in his letter to the Colossians:

I am now rejoicing in my sufferings for your sake, and in my flesh I am completing what is lacking in Christ’s afflictions for the sake of his body, that is, the church.
Colossians 1:24 NRSV

In the 2015 conference of the Mormon Transhumanist Association, MTA Director Ben Blair gave a presentation entitled “Come Follow Me: The Instrumental Atonement,” in which he shared various theories of atonement and proposed that its main purpose is to inspire us to follow Christ in taking responsibility for death and evil in the world and working to overcome them, with God's help.

See also anoint.