This work gathers three writings that share the same objective, the attempt to understand the changes in the way of living spirituality that took place during the so-called archaic period of ancient Greece. The religious currents that emerged at this time are of popular origin and link ancient elements of diverse origins with others that are just emerging. They are Orphism, Dionysianism, the mysteries, especially the Eleusinian, and Pythagoreanism. They also share an approach to achieve the proposed objective, which is to understand the rites, ideas, and lifestyles that were practiced for the attainment of these experiences of the sacred. The first part, The Mysteries of Eleusis, deals with one of the most enduring religious practices in Western history, and also takes us into the myth of Dionysus. The second, Orphism, attempts to extract the distinctiveness of their rites and practices. Since we do not have any direct text of Pythagoras' authorship, the third part focuses on Empedocles, who seems to us, among the cases that have come down to us, to be the one in which Pythagorean thought and the Orphic way of life are most clearly united.