B.H. Roberts is one of my favourite Latter-day Saint theologians, and I do look forward to “nerding it up” with him and a number of other people (e.g., Paul; Joseph Smith) in the life to come. In what has to be one of the best books on Mormon theology, Roberts offered the following comment on the motives behind the atonement of Christ and man’s participation in salvation. What strikes me as interesting is that Roberts (correctly) did not read 2 Nephi 25:23 as a statement supporting legalistic/Pelagian soteriology (see James Stutz’ excellent exegesis of the verse here).
Motive Force in the Atonement
What shall prompt a Deity to make such an atonement? The answer is: two attributes of the Deity now of a long time kept in the background, viz., love and mercy. They will supply motive for atonement. We have seen and considered at some length the helplessness of man in the midst of those earth conditions necessary to his progress, viz., knowledge of good and evil. God saw man's helplessness from the beginning; and:
So loved the world, that He gave His only begotten Son, that whosoever believeth on him might not perish but have everlasting life. For God sent not His Son into the world to condemn the world, but that the world through him might be saved (John 3:16-17).
This love prompts the Son of God to suffer for the individual sins of men as well as for the sin of Adam in Eden. He undertook to pay the penalty due to each man's sin, that there might be ground for man's justification under the law; that mercy might claim the sinner upon conditions that love may prescribe. And so Paul says:
By grace are ye saved through faith; and that not of yourselves; it is the gift of God (Eph. 2:8).
The law entered that the offense might abound. But where sin abounded, grace did <much> more abound; that as sin hath reigned unto death, even so might grace reign through righteousness, unto eternal life by Jesus Christ our Lord (Rom. 5:20-21).
And in harmony with this a Book of Mormon Prophet—the first Nephi—declares:
We know that it is by grace we are saved, after all that we can do (2 Ne. 25:23).
Man's Cooperation With God Necessary to Salvation
Notwithstanding this doctrine of being "saved by grace after all that men can do," yet in securing redemption from the consequences of man's individual sins, the cooperation of man is required; his acceptance, through faith, of God's plan for his salvation; acceptance of Jesus Christ and his redemptive work—obedience to him manifested by baptism, or burial in water for the remission of sin. The baptism being the symbol of the death, burial, and the resurrection of the Christ, and also the sign of the convert's acceptance of the Christ and the atonement he has made for the sins of men. Then also the acceptance of confirmation into membership of the Church of Jesus Christ by the laying on of hands, by which comes also the baptism of the Spirit—the Holy Ghost—bringing the convert into fellowship and union with God, by which he becomes spiritually alive—"born of the spirit," by reason of which he has become united to the spirit life of God, and hence put in THE WAY of eternal progress.
The gospel so far as the individual man is concerned is the "power of God unto salvation" (Rom. 1:16) to everyone that believes it, and obeys its prescribed ordinances, and its covenant of thereafter continuing righteousness. In the difference between the redemption from the transgression of Adam and redemption from man's personal sins, the one being free, unconditional, and universal; and the other being free, possible to all, but conditional, and therefore limited to those who comply with the conditions, there is to be observed nice discriminations in the justice of God. Free and universal redemption comes from the consequences of Adam's "fall," because that "fall" is absolutely necessary to the accomplishment of the purposes of God with reference to man's progress; without it nothing may be done for his progress. He must know the distinctions between good and evil in order to make progression, though that knowledge may not be acquired but by a "fall" from a state of innocence. Therefore, since that fall is necessary to these ends, justice demands that there be provided free and universal and complete and unconditional redemption from its consequences. But in the case of man's personal sins they are not absolutely necessary to the accomplishment of any general purposes of God. Of course, the earth-environment of man, including the broken harmonies as he finds them, may be necessary to the individual experience of man; but all that will abundantly come once men are at the same time free to choose, and good and evil is set before them. But what is here meant is that it is not an absolute necessity that individual men should sin, or that they sin without limit. Men can refrain from sin, if they will; the power is in them. They are brought into earth-life able to stand, "yet free to fall." They have power to choose good and to follow that instead of evil, if they so elect. Therefore, while it is eminently proper that the atonement of the Christ should be made to include satisfaction to justice for the personal sins of men, and the debt of suffering due to them should be paid, and paid vicariously, since man is powerless to offer expiation for himself, and it is needful that ample provision be made for the justification of man's pardon; yet it is also in accordance with justice that man shall cooperate with God in bringing about the blessed result of his deliverance from the consequences of his personal sins; and that conditions shall be required as necessary to participation in the forgiveness provided, such conditions as belief in and acceptance of the terms of atonement; repentance of sin, and a hearty cooperation with God in overcoming the evil, and its effects, in the human soul. (B.H. Roberts, The Truth, the Way, the Life: An elementary Treatise on Theology [ed. Stan Larson; Salt Lake City: Smith Research Associates, 1994], 505-7)