The Atonement of the Savoir cannot be fully explained or comprehended but ponder this one question, if you would.
For behold, I, God, have these things for all, that they might not if they would ;
But if they would not repent they must even as I;
Which caused myself, even God, the greatest of all, to tremble because of pain, and to bleed at every pore, and to suffer both body and spirit—and would that I might drink the bitter cup, and shrink—
Nevertheless, glory be to the Father, and I partook and my preparations unto the children of men.
Now, did your answer match that of the Savior's? I believe and hope it did. Alright, we understand the Atonement is not free, but when do we begin to access the power of the Greatest Sacrifice that ever happened?!?!? Answer: When we make our first Covenant, or promise, with God. We gain access to this cleaning power of the Atonement when we are baptized with God's Priesthood Authority! That's right! At Baptism We Promised to always remember the Savior and to always Keep the Commandments, and in return God Promises us the Holy Ghost; that "it might sanctify us," if we would only receive it.
We also promised at Baptism (and every time we renew our Covenants by taking the sacrament) to take His name upon us. If we promise "to take His name upon us" at Baptism, when do we Take his name upon us? Well we take it upon us when we make, and keep, another covenant, this time if the Temple of the Most High God!
"So if you have made covenants, keep them. If you haven't made them, make them. If you have made them and broken them, repent and repair them. It is too late so long as the Master of the vineyard says there is time. Please listen to the prompting of the Holy Spirit telling you right now, this very moment, that you should accept the atoning gift of the Lord Jesus Christ and enjoy the fellowship of His labor. Don't delay. It's getting late."- Elder Jeffery R. Holland 'Laborers in the Vineyard'
"...Sound Forth The Trumpet..."