HABERMAS, in a recent paper on 9/11, questions again the relationship between faith and knowledge in modernity. The modern outlook, excluding religion in the public realm, faces resistance that suggests another scenario for a post-secular world. He speaks about the dialogue between the two "rocks of ages" (Gould) only at the moral level, but the argument of the present paper highlights the reasons to give more weight to the cognitive role of religion. Recent studies, mainly in the realm of cognitive sciences, reveal the natural origin both of science and religion. In the realm of history and philosophy, other elements are suggested today for "faith" and "knowledge". In the Brazilian case, we emphasize the need for a common effort in face of threats such as creationism, and in favor of educational patterns that foster citizenship and sound knowledge.