The examples we have in Scripture make it clear that a person does not have to have an extensive understanding of every detail of the Gospel in order to be baptized (cf. Acts 2:37-41; 8:12-13; 8:34-39). However, Scripture makes some things very clear about baptism into Christ.
First, it is clear when a person is a suitable subject of baptism. Every example of baptism in the New Testament describes people who are old enough to come to faith. One must believe and be baptized (Mark 16:16). An infant can't believe.
Second, the method of baptism is clear. The Greek verb baptizō means "to dip, plunge, or immerse." In the examples in Scripture, baptism requires "much water" (John 3:23). One who is baptized goes "down into the water" and comes "up out of the water" (Acts 8:38-39).
Finally, the purpose of baptism is clear. In baptism, one desires to "put on Christ" (Gal. 3:27). A person is "buried with Him through baptism" (Rom. 6:4). Baptism is "for the remission of sins" (Acts 2:38), by which Christ allows you to "wash away your sins" (Acts 22:16).
If in our baptism we find that we were not a suitable subject of baptism, that we did not experience the proper method of baptism, or that we were baptized for some purpose other than that which is taught in Scripture, our baptism is not acceptable to God. Acts 19:1-5 describes just such a situation. Some who had received only the baptism of John, were taught about Christ. When they learned this they were baptized into Christ. If our baptism was not New Testament baptism into Christ we must follow this example.
Kyle Pope, july 2010