Long before modern religions, secretive groups known as mystery cults spread across the ancient world — offering hidden knowledge, initiation rituals, and something radical for their time: guaranteed salvation. In this episode of GL Deep Dives, we explore the ancient mystery cults that operated behind closed doors, including the Eleusinian Mysteries, the cult of Mithras, and the followers of Isis. What were these initiations really about? Why were their secrets protected under threat of...