1 John 5:6 This is the one who came by water and blood—Jesus Christ. He did not come by water only, but by water and blood. And it is the Spirit who testifies, because the Spirit is the truth.
This has been called “the most perplexing passage in the Epistle, and one of the most perplexing in the New Testament” (Barclay 127). If water represents baptism and blood the crucifixion this verse would indicate that there were some who believed Jesus became divine at his baptism and that the divine quality didn’t really participate in the death on the cross (after all, how can God die?). It is hard for us to wrap our minds around the statement that Jesus was fully human and fully divine. It is as hard as comprehending the Trinity and the church struggled to find adequate terminology. In the above passage the writer is saying God’s Spirit helps reveal the truth that Jesus was human just like us and died a death in that human body for us. If you have been present at the time of a baby’s birth you may remember water and blood being part of that process as well. Human life is a messy affair. How glorious of God to meet us in that mess!