What do Mormons believe about the sacrament?

The Mormon church believes each member makes a covenant with the Lord at baptism. In doing so, we are promising the Lord that we will take His name upon us, remember Him always, and strive to keep His commandments. In return, Mormons believe He will bless us with His Spirit. The blessings of the atonement—peace, forgiveness, a promise of eternal joy—will be upon us when we abide by the baptismal covenant.
But we all make mistakes after we are baptized. Though we are perfectly clean when we come up out of the water, none of us remain that way forever. What Mormons believe is that the weekly sacrament is a way to renew that baptismal covenant and start out fresh for another week. As long as a person is repenting and striving to keep the commandments, the taking of the sacrament will indeed renew that covenant and make them clean again.
To Mormons, the sacrament constitutes eating bread and drinking water symbolically in remembrance of Christ’s flesh and blood. Mormons do not believe the bread nor water is the literal body and blood of Christ. Members of the Mormon Church follow the teachings of Jesus as He outlined in what is known as the First Supper.
Luke 22:19-20: “And he took bread, and gave thanks, and brake it, and gave unto them, saying, This is my body which is given for you: this do in remembrance of me. Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you.”
Mormons believe that Joseph Smith received revelation about the proper practice of the sacrament during the restoration of the Mormon church. It was then that Joseph instituted the prayers that are recited word for word today in each Mormon sacrament meeting. Mormons have few prayers that are recited exactly the same every time they are said. The sacrament prayers, however, are an example of this.
At the beginning of the sacrament, priests (worthy male members of the church who have received the Melchizedek priesthood) kneel before the broken bread or cups of water and bless the sacrament. Then other worthy male priesthood holders pass the sacrament around in trays throughout the congregation. Every member who is living righteously may take the sacrament and renew their baptismal covenants. To Mormons, the sacrament is a time to reflect reverently upon the goings on of the past week and to think of the incredible sacrifice of our Savior Jesus Christ.