I am searching for a text I've since lost that I believe is a transcription of a conversation between someone and Derrida. The context may have been Heidegger's particular conception of philosophy and its incompatibility with the existence of / belief in God. I remember it as a lengthy quote.
I don't recall Derrida making that statement but the discussion of Augustine, Heidegger, Destruction/Deconstruction, and prayer comes up in Circumfession. Maybe this is what you are looking for: http://www.ubu.com/sound/derrida.html