Acts 8:36-37 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.
Matthew 3:15 And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him.
Baptism is a picture of salvation through the death, burial and resurrection of Jesus Christ. He too was baptised at the commencement of his ministry knowing that his death would be the ultimate sacrifice.
Matthew 28:19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
Baptism is an important step in the life of a new believer. It is a public declaration of salvation by grace through faith in the death, burial and resurrection of Jesus Christ.