This is the One who came by water and blood: A teacher named Cerinthus, who lived at the same time as John, taught a false idea. He said that “the Christ” came down as a spirit on the man Jesus at his baptism, but left him before Jesus died.
John teaches the truth. The baptism and death of Jesus confirmed his identity as the Christ, the Son of God. Jesus of Nazareth was and is truly the Christ, the Son of God, from the beginning and forever.