In Water Baptism by immersion and a direct commandment of our Lord, and is for believers only.

Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost  (Matthew 28:19)

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. (Romans 6:4)

Buried with him in baptism, wherein also ye are risen with him through the faith of the operation of God, who hath raised him from the dead. (Colossians 2:12)

And as they went on their way, they came unto a certain water: and the eunuch said, See, here is water; what doth hinder me to be baptized?

And Philip said, If thou believest with all thine heart, thou mayest. And he answered and said, I believe that Jesus Christ is the Son of God.

And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him.

And when they were come up out of the water, the Spirit of the Lord caught away Philip, that the eunuch saw him no more: and he went on his way rejoicing.  (Acts 8:36-39)