This paper tries to demonstrate that religion, in general, is a constituent element of modern societies, despite the extreme rationalization of the various forms of eighteenth-century thought, the triumph of scientific thought in the nineteenth century and the massive secularization of the twentieth century from science, politics, economy, literature and philosophy. That is, inversely to what was expected -a new century atheist, irreligious and extremely rationalistic-, our time has seen a return to religion again; return determined by new spiritualities, strengthening of traditional faiths and radicalism, and religious extremism, with which we live day by day.