The Adorno discussions have dealt in part with the religious influences on the thought of Frankfurt School figures. I came across this in a review by theologian Paul Tillich of Herbert Marcuse's 1941 book, Reason and Revolution: Hegel and the Rise of Social Theory. It was in the final issue of their flagship journal, the last four issues of which were published in English as Studies in Philosophy and Social Science 9:3 (1941). Part of what he wrote was this:
As one who agrees in all important points with Marcuse's book, I should like to make the following criticisms and suggestions. ... the section on Hegel should be substantially enlarged by a full treatment of Hegel's philosophy of religion and an adequate treatment of his aesthetics. Even a critical social theory cannot avoid an "ultimate" in which its criticism is rooted because reason itself is rooted therein. Otherwise criticism itself becomes positivistic and contingent. And no successful revolution can be made without a group of people who - however critical they may be of any special religious symbol - believe that the "freedom of personality" is the meaning of existence and are ready to live and to die for this belief. The pervasive disappointment over the last revolutions demonstrates this irrefutably. Feuerbach is right in showing that there is wishful thinking in religion and Marx is right in showing that the bourgeois religion belongs to the whole of bourgeois ideology. But it is a wrong generalization, derived from a metaphysical materialism, to dismiss religion itself as ideology. The transformation of philosophy into critical theory does not imply such a consequence at all.