It was a match-up made in Q&A heaven: two pugilists of opposing convictions going head-to-head in a debate about the existence of God.

Australia's highest-ranking Catholic and Sydney's archbishop, Cardinal George Pell, spent an hour with evolutionary biologist and celebrity atheist, Professor Richard Dawkins taking questions covering everything from evolution, resurrection and eternal damnation.

Frustration and something bordering on barely concealed mutual disdain boiled over more than once during the ABC television show.

Charles Darwin was claimed as a theist by the cardinal, because Darwin ''couldn't believe that the immense cosmos and all the beautiful things in the world came about either by chance or out of necessity'' - a claim disputed by Professor Dawkins as ''just not true''.