Listen to the Apostle Paul's vivid description of baptism in Romans 6:3-5; "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 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. For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrections Here the Bible clearly describes the baptism which was taught and practiced in the early church and which puts one "into Jesus Christ" as a burial. Paul said, "We are buried with him by baptism into death." Again, in Colossians 2:12, we read that we are "buried with him in baptism." Nowhere in the Bible is the action of Christian baptism described as being anything other than "a burial" or an immersion in water. In Mark 1:5, we find that John baptized in water. The passage reads, "And there went out unto him all the land of Judea, and they of Jerusalem, and were all baptized of him in the river of Jordan." Again, in Mark 1:9, we find that Jesus was baptized in the Jordan. "And it came to pass in those days, that Jesus came from Nazareth of Galilee, and was baptized of John in Jordan." In John 3:23, we find John's reason for selecting the place where he baptized those who came to him. "And John also was baptizing the Aenon near to Salim, because there was much water there; and they came and were baptized."
Now let us notice carefully the baptism of the Ethiopian eunuch by Philip the evangelist. The two men were riding in a chariot. Philip was preaching Jesus unto the eunuch. In Acts 8:36, we read "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, and 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". From these verses of scripture we find that baptism requires "much water" and a "going down into water". We see that it is a "burial" in water and a "resurrection". Also we see it requires a "coming up out of the water".
Only immersion fits the New Testament description of Christian baptism. If you believe in Jesus and want to receive the remission of your sins; as a penitent person, be buried with Christ in baptism to "wash away your sins."(Romans 6:3-4 and Acts 22:16)