The Middle East has always been a crossroad to soldiers of fortune, traders and missionaries. We should not be surprised, therefore, to find some of the most exotic religions in the world there. One of these would be the Mandaeans, whose name comes from the Aramaic 
(manda ‘ḥay, “teaching/knowledge of life.”)
Almost at the same time as Christianity appeared in the Middle East, gnostic (from Greek γνῶσις, gnosis, “knowledge”) religions began to appear. The gnostic religions are very different each other, yet show a remarkable ability to take over beliefs from Indian religions, Greco-Roman religions, Judaism and Christianity itself. For over 300 years, Christianity resisted incursions of gnostic religion into its faith. One of these, Manichaeism — a dualist, anti-body form of Gnosticism — provided a major threat to orthodox Christianity. In fact, Augustine of Hippo (354-430), the great theologian and saint, was a follower of Manichaeism before his conversion to Christianity.
The Mandaeans are within this large tradition of gnostic religions — one of many that interacted with Christianity in the region for centuries. It is estimated that Mandaeism took form in the 1st through 3rd centuries AD in Iraq, at the same time and place where Eastern Christianity was beginning to grow.
Traditionally, they were found in southern Iraq along the great rivers, which isn’t surprising. Water is very important for Mandaeans, since baptism is one of their major and frequently performed rituals. In fact, they are sometimes referred to as “baptizers.” Many years ago, I had an Arabic teacher from southern Iraq who told me she was a “Baptist.” I thought it strange because Baptists Christians are extremely rare in the Middle East, but one day I asked her if she was manda ‘ḥay. She lit up and said, “You know of us?” She was, of course, a Mandaean. While fascinated, I could not say I knew a lot about her faith.
As “baptizers,” Mandaeans hold John the Baptist in extremely high regard, though they do not consider him divine. They look upon Jesus as a false Messiah who corrupted the message of John the Baptist.
Mandaeans believe in a supreme deity from whom there are emanations into the created world. In their teaching, human beings were originally astral beings (stars) that have fallen to their present state. Such emanations from an original divine being are common in gnostic religions.Through observing the “Mysteries” — secret rituals — the believer is able to move through higher states of being until ultimate returning to his astral identity.
As is often the case in gnostic religions, there is a strict “caste” system. The “enlightened” are those who have achieved the teaching of life. Among the enlightened are the priests who hold the highest in rank. The majority of believers form the laity, whose task it is to purify themselves through repeated baptisms and to seek ever deeper awareness of the manda ‘ḥay until ultimately reaching enlightenment.
Most of the religious minorities we have dealt with in the past several weeks are secretive. For many of them, however, secrecy is a survival strategy, a way to protect themselves from the dominant religion in the region. Secrecy for gnostic religions, however, is an essential part of a faith which places great stress on the esoteric, i.e. secret, saving knowledge.
Time and history may have finally caught up with this religion, though. The Gulf War which began in 2003 forced many Mandaeans to flee. Living between Baghdad and the Persian Gulf along the two rivers, they found themselves in a battle zone. Already a tiny, minority faith, many Mandaeans fled to different places around the world — including the United States, where a small Mandean community of about 2,000 people resides in Worcester, Massachusetts.
At present it is estimated that they are between 60-70,000 Mandaeans in the entire world. Whether they will survive the 21st century is an open question.
Related:
Religious Minorities in the Middle East — Introduction
Religious Minorities in the Middle East, Part 1: The Yazidis