Without it [the atonement of the Savior], no man or woman would ever be resurrected. From Adam’s time to the time of Jesus, men died—millions of them. But not a single one of them ever came out of the grave as a resurrected person until that glorious morning when Jesus was resurrected.
Without his victory over death, they never would have come out of their graves, worlds without end. It took the atonement of Jesus Christ to reunite the bodies and spirits of men in the Resurrection. And so all the world, believers and nonbelievers, are indebted to the Redeemer for their certain resurrection, because the Resurrection will be as wide as was the Fall, which brought death to every man.
There is another phase of the Atonement which makes me love the Savior even more and fills my soul with gratitude beyond expression. It is that in addition to atoning for Adam’s transgression, thereby bringing about the Resurrection, the Savior by his suffering paid the debt for the personal sins of every living soul that ever dwelt upon the earth or that ever will dwell in mortality upon the earth.
But this he did conditionally. The benefits of this suffering for our individual transgressions will not come to us unconditionally in the same sense that the Resurrection will come regardless of what we do. If we partake of the blessings of the Atonement as far as our individual transgressions are concerned, we must obey the law.
… When we commit sin, we are estranged from God and rendered unfit to enter into his presence. No unclean thing can enter into his presence. We cannot of ourselves, no matter how we may try, rid ourselves of the stain which is upon us as a result of our own transgressions. That stain must be washed away by the blood of the Redeemer, and he has set up the way by which that stain may be removed. That way is the gospel of Jesus Christ.
(Marion G. Romney, “We Cannot Rid Ourselves of Our Transgressions,� New Era, Apr. 1983, p. 47)