July 16, 2023. Ahvaz, Khuzestan, Iran. Mandaeans or simply as Sabians are an ethnoreligious group who are followers of Mandaeism. They believe that John the Baptist was the final and most important prophet. They may have been among the earliest religious groups to practice baptism, as well as among the earliest adherents of Gnosticism, a belief system of which they are the last surviving representatives today.