Yesterday John ended by saying that the ones who overcome the world are those who believe that Jesus is the Son of God. Now John focuses on what we must believe about Jesus. He is the one who came by water and blood. He came by water when He was baptised and began His public ministry. He came by blood when He shed His blood and died on the cross. John was likely speaking against teachings like that of Cerinthus who taught that Jesus was a man and that the divine Christ descended on Him at his baptism and departed before His crucifixion. He denied that Jesus came by both water and blood. The third testimony to Jesus being the Christ is the Spirit. The Holy Spirit testified at Jesus’ baptism. John makes clear that the Holy Spirit is a different person, not the Christ descending on Jesus only to leave again before His crucifixion. The Spirit’s witness also came through the prophets who prophesied about the coming Christ. The Spirit’s testimony is true because the Spirit is the truth (in the same way God is light and love). All three testimonies agree that it is one divine person who was baptised and crucified.
If the testimony of man can be accepted, when it is adequately verified (Deut 19:15), then the testimony of God, who is greater (and who is truth) should be accepted. God’s testimony is that He has given us eternal life through His Son. God’s testimony simply needs to be believed. He has said that eternal life is found in Jesus and without Jesus no one can have eternal life. If we believe this, then we have the assurance that we have life. If we do not believe this, then we call God a liar.

Salvation can be a sure thing. Doubt about our salvation comes when we look to the wrong things to provide assurance, even things like abiding in Christ. Salvation is based on a promise, a promise from God Himself and born witness through the Spirit, Jesus’ baptism, and Jesus’ shed blood on the cross.