The word "baptize" comes from a Greek word which means to "dip" or "immerse." The word was often used in the ancient world to describe the act of dipping a cup in a stream, or washing clothing. To "baptize" something is literally to immerse it in water.

John the Baptist was the first person in the New Testament to baptize people. He baptized those who repented publicly from their sins and wanted to follow God in faith. Their baptisms took place in the Jordan River as a witness to their community.

When Jesus began his public ministry, he did so by being baptized by John. Of course, he was not repenting of his sins, since he is the sinless Son of God. Rather, he was giving witness to his faith in his Father and supporting John's work of preaching and baptizing.

Later, Jesus commanded all his disciples to continue this work of baptizing: "Go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19). Baptism thus began with John and is commanded by Jesus Christ for us today.