What you believe is determined by where you look for proof. If you want to believe the truth about Christ, then there are four sources of evidence offered by John as he closes his letter to the church. He says there are the testimonies of the water, the blood, the Spirit, and finally the testimony of God. All of these are testified to by John as an eye-witness to the life of Christ on earth. We can be confident in our faith based on these four testimonies.