Moroni Chapter 5

1 The manner of administering the wine-Behold, they took the cup, and said:

2 O God, the Eternal Father, we ask thee, in the name of thy Son, Jesus Christ, to bless and sanctify this wine to the souls of all those who drink of it, that they may do it in remembrance of the blood of thy Son, which was shed for them; that they may witness unto thee, O God, the Eternal Father, that they do always remember him, that they may have his Spirit to be with them. Amen.

verse 2 (also applies to Moroni 4:3) The ordinance of the sacrament is a vital and indispensable ordinance and covenant that is intimately associated with the process by which we grow spiritually, including the processes of justification and sanctification (please review Justification and Sanctification in Ye Shall Know of the Doctrine, volume 1, chapter 17). During the ordinance, we renew the covenant of obedience we first made at the time of our baptism. We covenant to strive to remake ourselves to become like him. In association with the ordinance of the sacrament, the Holy Ghost functions not only to remove the penalty of sin (justify us) but to burn out of our soul an increment of the natural self and bestow upon us incremental gifts of the Spirit which we must acquire in our quest to become like the Savior and obtain his attributes for ourselves (sanctify us).

The emblems of the sacrament are, of course, symbolic of the Savior's flesh and blood, and hence, symbolic of his atonement.