If you are going to scoff at evidence, scoff big. This was the thought that flashed through my mind when the atheist philosopher AC Grayling challenged me during our debate on The Big Conversation to nominate “one thing, just one thing, that Christianity has introduced that doesn’t have some source, some parallel with previous and with other civilisations”. So might a geographer have been challenged to prove that the earth is not flat. So might an ornithologist have been challenged to prove that birds have feathers. The difficulty is not to muster evidence. The difficulty is rather the opposite: that the evidence is everywhere.