22 After this, Jesus and his disciples went out into the Judean countryside, where he spent some time with them, and baptized. 23 Now John also was baptizing at Aenon near Salim, because there was plenty of water, and people were coming and being baptized. 24 (This was before John was put in prison.) (John 2:22-24 NIV).
Both John the Baptist and Jesus’ disciples practiced baptism before Jesus died on the cross. In those days, of course, none of Jesus’ followers understood the theology of Christian baptism, because Jesus had not yet been given as a sacrifice for our sins. They did not completely understand the concept of death to sin nature and new life in the Risen Savior (Colossians 2:12).
However, they did understand that baptism was about submission to God and repentance (Matthew 3:6-8). The baptized person has the responsibility to be a changed person. Please, do not brag to me about your baptism if you are not a changed person from what you were before you became a Christian. I don’t want to hear about some mystical experience you had: I want to hear about how you once were a sinner, but God saved you.