Most people assume they know what they mean when they use the word "God." They mean a powerful old guy in the sky ready to obliterate us if we do wrong but basically benevolent, if a little senile. The Christian doctrine of the Trinity shows us God is vastly more interesting. God is actually fleshed among us in Jesus, poured out on us in the Holy Spirit's intoxication of the church. God is three divine persons in perfect harmony and beauty--and God...