Christian atheism is a form of Christianity that adopts the teachings, narratives, symbols, and/or communities associated with Jesus without accepting the literal existence of God. Christian atheism takes many forms, and may include an ethics system, aspects of cultural Christianity, and a variety of Christian theological positions. Prominent Christian atheist thinkers include Thomas J. J. Altizer (a leader in Death of God theology), John D. Caputo (a progenitor of "weak theology" in which "God doesn't exist; God insists"), William Hamilton (who advocated following Jesus in a Godless world, similar to Jesuism), and Slavoj Žižek (who said Jesus himself became an atheist on the cross). Thomas Ogletree, Frederick Marquand Professor of Ethics and Religious Studies at Yale Divinity School, lists these four common beliefs: the assertion of the unreality of God for our age, including the understandings of God which have been a part of traditional Christian theology; the insistence upon coming to grips with contemporary culture as a necessary feature of responsible theological work; varying degrees and forms of alienation from the church as it is now constituted, and; recognition of the centrality of the person of Jesus in theological reflection. According to Paul van Buren, a Death of God theologian, the word God itself is "either meaningless or misleading". Van Buren contended that it is impossible to think about God and said: "We cannot identify anything which will count for or against the truth of our statements concerning 'God'." The inference from these claims to the "either meaningless or misleading" conclusion is implicitly premised on the verificationist theory of meaning. Most Christian atheists believe that God never existed, but there are a few who believe in the death of God literally. Thomas J. J. Altizer is a well-known Christian atheist who is known for his literal approach to the death of God. He often spoke of God's death as a redemptive event.