...Jesus included baptism in the Great Commission just before ascending into heaven.
Baptism is one of the two sacraments He instituted for His Church, His Kingdom.
...On the day of Pentecost, Peter preached of the necessity of baptism for the remission of sins, in Acts 2:38 thru baptism, we come into contact with the blood of Christ, as the Bible says in Romans-6: It is necessary for the forgiveness of sins and the gift of the Holy Spirit.
...The only legitimate baptism is by immersion, in the name of the Father, Son and Holy Spirit.