Over the centuries we have studied scripture, looked at the world and our own experience and tried to describe concisely how God is present and active. Today is Trinity Sunday. The doctrine of the Trinity is our best attempt to describe God from a vantage point that knows of the bush on the mountain, the carpenter from Galilee, and the light of our own spiritual experience. Any even cursory reading of the Old Testament reveals God at work. Waters part and bushes burn.
Kingdoms rise and fall.
This God is real, but there is more. Jesus is born. He lives and dies as one of us, but rises again to bring eternal life. The disciple John articulates what he has seen and heard in his years with Jesus. At some point, many years later, a Gospel is written.