Trinity Sunday focuses our attention on the doctrine of the Holy Trinity, the distinctive Christian teaching on God. The Athanasian Creed, in which this doctrine was first set forth in detail, declares that no one can be saved unless he believes it. But it places a severe burden on our understanding. It is not easy to believe that God can be one and three at the same time. A contemporary theologian has said of the Trinity, "While one may be in danger of losing his soul by denying it, he is in danger of losing his wits in trying to understand it." We are dealing here with a paradox and a mystery, and the church has always rejected easy ways of trying to solve it. I lectured once on this subject to a group of religious educators, and in the discussion that followed, one teacher said, "I have…