Who doesn't love a good old-fashioned showdown between an atheist and a religious convert? The possibilities for awkward silences, blasphemy and overturned tables are endless, plus one of them used to be England's prime minister.

On one side you had novelist and author Christopher Hitchens, a loudly, proudly self-avowed cancer-stricken writer whose brush with death has done nothing to disavow his long-held convictions that God is Not Great, as he titled his recent book.

On the other was former British PM Tony Blair, a recent Roman Catholic convert who became the latest straw man to go up against the erudite Hitchens in a debate over the existence of a divine being. The pair squared off on Friday at Roy Thomson Hall in Toronto for a philosophical debate on the moral merits of religion.

The surprises? Mr. Hitchens, who lives in Washington, D.C. has had a Christmas tree as long as he's been a father and observes Passover. He discovered his family's Jewish roots late in life; his wife, Carol Blue, is also Jewish.

And Mr. Blair's father, Leo, a retired law professor, is a militant atheist. The long-time politician also revealed in his recently released memoir, A Journey: My Political Life, that he has always been more interested in religion than politics.

For Mr. Blair, who converted to Catholicism after leaving office in 2007, religion plays the most central of roles, both personally and in his worldview.