In the Arab world, theocratic Islamism is on the rise, in the USA, fundamentalist evangelical sects are proliferating, attempting to replace Darwin's theory of evolution with biblical revelations, and in the former Eastern Bloc countries, Christian denominations are gaining ground. In light of these developments, it is pertinent to revisit the argumentation patterns used in religious criticism so far and to question whether they remain valid for the 21st century. Or do those who claim that religious consciousness is an inherent part of humanity and must therefore persist as long as there are humans have a point? Kellner examines various forms of religious criticism from early scholasticism through the Enlightenment to Hegel's approach of replacing the personified God with logic or the world spirit. He identifies Feuerbach as a turning point in religious criticism, who declares the question of God's existence to be outdated and instead focuses on how God enters the minds of people. This approach inevitably leads to Marx, who argues that the critique of religion must transition to the critique of the misery from which religion thrives, and to Freud, for whom religious content is a projection of human family life. Finally, Kellner incorporates important theses from morally motivated religious critics such as Bucharin and Most into his considerations.