2. Why did John the Baptist perform immersions?

² John the Baptist was sent to baptize members of the nation of Israel who were dedicated to Jehovah God and obligated to keep the Law covenant but who were guilty of sins against Jehovah’s arrangement and needed to repent. By getting Israelites to repent in order to be cleansed of sins and by baptizing them publicly in symbol of repentance, he was preparing the way for God’s covenant people to come to the Christ.​—Luke 3:3, 4; Acts 19:4.

John’s baptism, however, was not to continue indefinitely, for he said concerning Christ Jesus: “That one must go on increasing, but I must go on decreasing.” (John 3:30) What was due to take its place was the Christian baptism that Jesus mentioned at Matthew 28:19. So when would that be? John’s baptism was only for those in the Law covenant relationship with Jehovah, and that covenant was in force or effect only until 33 C.E.