Here is an interesting intellectual debate over the existence of God between two extremely bright men.
Bios taken from Wikipedia.org:
Richard Dawkins, FRS, FRSL (born 26 March 1941) is a British ethologist, evolutionary biologist and popular science author. He is a professorial fellow of New College, Oxford.Dawkins came to prominence with his 1976 book The Selfish Gene, which popularised the gene-centred view of evolution and introduced the term meme. In 1982, he made a widely cited contribution to evolutionary biology with the theory, presented in his book The Extended Phenotype, that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, including the bodies of other organisms.
Dawkins is a prominent critic of creationism and intelligent design. In his 1986 book The Blind Watchmaker, he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the observed complexity of living organisms, and instead described evolutionary processes as being analogous to a blind watchmaker. He has since written several popular science books, and has made regular appearances on television and radio programmes, predominantly discussing the aforementioned topics.
Dawkins is an atheist, secular humanist, skeptic, scientific rationalist, and supporter of the Brights movement. He has widely been referred to in the media as "Darwin's Rottweiler", by analogy with English biologist T. H. Huxley, who was known as "Darwin's Bulldog" for his advocacy of natural selection. In his 2006 book The God Delusion, Dawkins contends that a supernatural creator almost certainly does not exist and that faith qualifies as a delusion − as a fixed false belief. As of November 2007, the English language version had sold more than 1.5 million copies and had been translated into 31 other languages, making it his most popular book to date.
Alister E. McGrath (born January 23, 1953) is a Christian theologian, with a DPhil in molecular biophysics, as well as an earned Doctor of Divinity degree from Oxford, noted for his work on historical, systematic and scientific theology. In his writing and public speaking, he promotes "scientific theology" and opposes antireligionism. McGrath was until recently Professor of Historical Theology at the University of Oxford, but has now taken up the chair of Theology, Religion and Culture at King's College London since September 2008. Until 2005, he was principal of Wycliffe Hall.