We must learn and obey certain principles and ordinances in order to be a true follower of Christ. Principles are truth, and ordinances are rites or ceremonies. Faith in the Lord Jesus Christ and repentance are the first two principles of the gospel. The first ordinance of the gospel is baptism. Faith in the Lord Jesus Christ, repentance, and baptism bring forgiveness for sins through the Atonement of Jesus Christ.
There are several reasons for the ordinance of baptism: 1) To show obedience. Jesus was baptized even though He was sinless. 2) To become a member of the Church of Jesus Christ. 3) To receive the gift of the Holy Ghost. 4) To enter the Celestial Kingdom.
The proper mode of baptism was revealed to Joseph Smith by the Lord. Jesus told him that a person with proper priesthood authority to baptize "shall go down into the water with the person who has presented himself or herself for baptism …. Then shall he immerse him or her in the water, and come forth again out of the water" (Doctrine and Covenants 20:73-74). Immersion is a requirement and is symbolic of death, burial, and resurrection. A newly baptized individual starts a new way of life. Baptism by immersion under proper priesthood authority is the only acceptable means of baptism.
Every person who is eight years old or older and is accountable or responsible for his or her actions needs to be baptized. Little children younger than eight are not capable of sinning and do not require baptism. People who are mentally incapable of knowing right and wrong do not need baptism.
When we are baptized we make covenants with God that we will: 1) Come into the fold of God; 2) Bear one another's burdens; 3) Stand as witnesses of God at all times and in all places; 4) Serve God and keep His commandments. When we keep the covenants made at baptism, the Lord promises to: 1) Forgive our sins; 2) Pour out His Spirit more abundantly upon us; 3) Give us daily guidance and the help of the Holy Ghost; 4) Let us come forth in the First Resurrection; 5) Give us eternal life. (See Acts 2:38; Mosiah 18:7-17; Doctrine and Covenants 20:77; 49:13.)
Baptism is called a new birth because it brings a new way of life. Baptism is a great blessing because it gives us a new start on our journey towards eternal life.