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.

Washington, D.C. is in many ways a city of extremes. Starland Vocal Band, Marvin Gaye, Duke Ellington, Nils Lofgren, Chuck Brown, Henry Rollins, Fugazi and Trouble Funk all hail from D.C. In the early '70s, the music style go-go originated here, and has remained a local craze ever since. Dave Grohl sits down with Trouble Funk's Big Tony Fisher to talk about go-go, and explores its origins with Chuck Brown, the genre's undisputed godfather.
He also chats with Don Zientara, owner of Inner Ear Studios, which the Virginia-raised Grohl says 'produced the entire soundtrack of my youth,' as well as with members of the harDCore band Bad Brains and Ian MacKaye of Teen Idles, Minor Threat and Fugazi, who all recorded at Inner Ear over the decades. The song 'The Feast and the Famine' is recorded during this episode.

After 400 BC, a new philosophy was born in South east Asia, generated from the ideas of Buddha, a mysterious Prince from India who gained enlightenment while he sat under a large, shapely fig tree. He remains one of the most legendary and influential of all religious progenitors, but what of his actual life? In this biographical documentary, director David Grubin tells the historical tale of Gautama Buddha (563-483 BC), from his initial enlightenment through his death around the age of 80. In the process, Grubin makes an unusual point: that Gautama never once claimed to be God or God's emissary, but instead sought to find a way to bring peace and alleviation from suffering to others in a cruel and often insane world. In telling this story, Grubin combines a number of elements including original animations, testimony by contemporary Buddhists such as the 14th Dalai Lama Tenzin Gyatso, glimpses of sculptures and paintings that help tell Gautama's story, and much more. Narrated by Richard Gere

In the last episode of the series, Freeman examines different faiths' views on miracles, meeting a man who survived falling 47 storeys and a cancer patient who believes his illness can be cured by prayer.

In the second episode of the series, Morgan Freeman looks into prophecies of violent cataclysms, and the strife of ages past, in an attempt to determine how the world will end.

In the fourth episode, Morgan Freeman examines how different faiths see the creation of the world, taking him on a journey to the Vatican, Cairo and the jungles of Guatemala.