Given the degree of popular fascination with Gnostic religions, it is surprising how few pay attention to the one such religion that has survived from antiquity until the present day: Mandaism. Mandaeans, who esteem John the Baptist as the most famous adherent to their religion, have in our time found themselves driven from their historic homelands by war and oppression. Today, they are a community in crisis, but they provide us with unparalleled access to a library of ancient Gnostic scriptures, as part of the living tradition that has sustained them across the centuries. Gnostic texts such as these have caught popular interest in recent times, as traditional assumptions about the original forms and cultural contexts of related religious traditions, such as Judaism, Christianity, and Islam, have been called into question. However, we can learn only so much from texts in isolation from their own contexts. Mandaean literature uniquely allows us not only to increase our knowledge about Gnosticism, and by extension all these other religions, but also to observe the relationship between Gnostic texts, rituals, beliefs, and living practices, both historically and in the present day.