He that believeth and is baptized shall be saved; but he that believeth not shall be damned. Mark 16:16

And were baptized of him in Jordan, confessing their sins. Matthew 3:6

 And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness.  Matthew 3:15.

 ...Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost. Acts 2:38

The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ! Peter 3:21

We believe that all believers in Christ must be baptized by water according to their own personal testimony.

We don't baptize children because they are too small to testify anything.

Then Philip began with that very passage of Scripture and told him the good news about Jesus. As they traveled along the road, they came to some water and the eunuch said, "Look, here is water. Why shouldn't I be baptized?" And he gave orders to stop the chariot. Then both Philip and the eunuch went down into the water and Philip baptized him. When they came up out of the water, the Spirit of the Lord suddenly took Philip away, and the eunuch did not see him again, but went on his way rejoicing. Acts.8:35-39