Tonight I will send a postcard to my university teacher in Systematic Theology at Halle University in Germany. I might choose a postcard showing Rublev’s so called icon of the Trinity, just because I was advised by a priest not to mention this all too famous icon this morning because everyone mentions it on Trinity Sunday. I will write this postcard because I remember him telling us, send me a postcard whenever you really preach a sermon on the Trinity, and today I am doing just that. For my professor the Trinity was just a hybrid concept, a theological construct. He couldn’t see how the doctrine of the Trinity could connect with any experience of the Christian faith.