Two Jewish scientists, one a Christian, the other an atheist travel back in time to first century Palestine. There they meet Christ and one has to reconcile his faith with reality while the other’s lack of faith is challenged. The writing is comic-bookish, but the plot is clever: “The Didymus Contingency” is a page-turner. Robinson’s theology and his Jesus are overly glib, but his portrayal of a friendly Christ is appealing. The power of the resurrection story makes up for the book’s weaknesses.