D&C 88

Alma asked Zeezrom -

"Believest thou in the power of Christ unto salvation?"  (Book of Mormon | Alma 15:6)

In my mind the power of Christ is the power of the atonement.  This power is demonstrated in the law of the resurrection and the laws of justification and sanctification.

In modern day we learn -

"....verily I say unto you, that which is governed by law is also preserved by law and perfected and sanctified by the same."  (Doctrine and Covenants | Section 88:34)

And -

"That which breaketh a law, and abideth not by law, but seeketh to become a law unto itself, and willeth to abide in sin, and altogether abideth in sin, cannot be sanctified by law, neither by mercy, justice, nor judgment."  (Doctrine and Covenants | Section 88:35)

Obviously, as we strive to be governed by "God's" law or eternal laws, it the is power of Christ that justifies and sanctifies us.