|(Church in Detroit)|
When an atheist calls religion "evil" or "immoral" they are, mostly unknowingly, drawing upon Christian morality. This is because, if there were no God, nothing is intrinsically evil or immoral. (Many intellectual atheists affirm this. Hence, they resort to utilitarianism, or emotivism.)
Jürgen Habermas, arguably the greatest philosopher of our time (at least tied for #1), is not a Christian. But note what he says about morality. Habermas writes:
"Christianity has functioned for the normative self-understanding of modernity as more than a mere precursor or a catalyst. Egalitarian universalism, from which sprang the ideas of freedom and social solidarity, of an autonomous conduct of life and emancipation, of the individual morality of conscience, human rights, and democracy, is the direct heir to the Judaic ethic of justice and the Christian ethic of love. This legacy, substantially unchanged, has been the object of continual critical appropriation and reinterpretation. To this day, there is no alternative to it. And in the light of the current challenges of a postnational constellation, we continue to draw on the substance of this heritage. Everything else is just idle postmodern talk." (Jürgen Habermas, Time of Transitions, pp. 150–51.)
In Good God: The Theistic Foundations of Morality, philosophers David Baggett and Jerry Walls write:
"A picture of reality in which all life is no more than a product of blind naturalistic forces and fortuitous collocations of molecules is fundamentally less adequate to underwrite morality than a personal universe created and sustained by a perfectly loving God. Traditionally conceived moral obligations, while residing comfortably in a theistic universe, are incongruous in a purely naturalistic world."
Atheist J.L. Mackie agreed. For him, "without God it's unlikely that morality, given its odd features, is true." Mackie wrote: "Moral properties constitute so odd a cluster of properties and relations that they are most unlikely to have arisen in the course of events without an all-powerful god to create them."