Baptism is a Pledge
A person is pledging their conscience when they are baptized.
This water symbolizes baptism that now saves you also - not the removal of dirt from the body but the pledge of a clear conscience toward God. It saves you be the resurrection of Jesus Christ.
1 Peter 3:21
Baptism is by Submersion
The Greek root "bap-to" means to be "submerged", "dipped", or "wholly covered".
This submersion is a type or symbol of the death and burial of the old self and the birth of a new life in Christ.
Therefore, we have been buried with Him through baptism.
Having been buried with Him in baptism, in which you were also raised up.
Baptism is in Jesus' Name
The Apostles understood Jesus' instructions perfectly and followed them faithfully.
Go therefore and make disciples of all nations, baptizing them in the name of the Father, and the Son, and the Holy Spirit.
Peter said to them, "Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit.
...they had simply been baptized in the name of Jesus Christ.
When they heard this, they were baptized in the name of the Lord Jesus.