3 Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
6 Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin. Romans 6
The purpose of baptism is to remove all previously committed sins, giving a person a fresh start, and to take on himself specific covenants. A covenant is a promise between man and God, with God setting the terms of the agreement.
Mormon beliefs require the baptism all those over the age of eight who choose to join the church as a convert. This allows a person who has just come to understand and to know what God wants of them to be cleansed of the things they did prior to gaining a testimony of the restored gospel. They then start fresh when they become a member of the church.
At baptism, members covenant to take on themselves the name of Jesus Christ and to keep the commandments to the best of their ability. In return, God promises to bless them and to allow them to return home to Him someday if they do as He asks.
Children are not baptized until they’re eight years old, the age of accountability. Children younger than eight are redeemed through the atonement of Christ, and should an infant or young child die before reaching the age of eight, he or she returns directly to God, not accountable for any choices made prior to that time.
Children eight and older are accountable for those things in their control and that they know about. Parents are accountable for teaching their children gospel truths and helping them to live those truths.
Shortly after baptism, a person will be made a member of the Church of Jesus Christ of Latter-day Saints (often known as the Mormons) and will receive the gift of the Holy Ghost.
Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
Having repented of previous sins, and now knowing what God wants them to do, new members are able to make a new start and begin to live a Christ-centered life that is focused on eternity. The Holy Ghost guides them safely through this new life and helps them to receive confirmation from God that they’re on the proper path and to make choices as new situations arise.
If Jesus was baptized, having no sin of which to be forgiven, we can be certain it is required of us, with all our imperfections and need of spiritual guidance.