Atheist and scientist Richard Dawkins visits England, America and Israel interveiwing prominant people of faith; Islamic, Hasidic Jews, and the new Christian sects popping up throughout the world, and expressing his view of the extent to which this fanaticism has degraded our civilisation, and will continue to degrade it. "The God Delusion" explores the unproven beliefs that are treated as factual by many religions and the extremes to which some followers have taken them. Dawkins opens the programme by describing the "would-be murderers ... who want to kill you and me, and themselves, because they're motivated by what they think is the highest ideal." Dawkins argues that "the process of non-thinking called faith" is not a way of understanding the world, but instead stands in fundamental opposition to modern science and the scientific method, and is divisive and dangerous.

Dawkins opines that the moral framework of religions is warped, and argues against the religious indoctrination of children. He discusses specifically the idea of religion seen as a virus in the sense of a meme. He begins by explaining how a child is genetically programmed to believe without questioning the word of authority figures, especially parents – the evolutionary imperative being that no child would survive by adopting a sceptical attitude towards everything their elders said. But this same imperative, he claims, leaves children open to infection by religion.