Conversation so far:
What is Mandaeism's relationship with Cosmology?
Mandaean theology is not systematic as there's no one single authoritative account of the creation of the cosmos, but rather a series of several accounts.
What were some of Mandaeism's accounts of the creation of the cosmos?
Mandaean religious texts recall a discrete division between light and darkness. Ptahil, the third emanation, fills the role as the creator of the material world.
What divides the Ginza Rba scriptures?
Ginza Rba is divided into two halves—the Genzā Smālā and the Genzā Yeminā.
Can you elaborate on the division of Ginza Rba scriptures?
Genzā Smālā has colophons that suggest Mandaeism may date to the late Parthian Empire.
Around what time were Mandaeism theories created?
According to most scholars, Mandaeaism originated sometime in the first three centuries AD, but some scholars view Mandaeanism dating back to pre-Christian times.
Are there any other interesting aspects about this article on Mandaeism?
Unlike other religions, Mandaean baptism is not a one-off event but is performed every Sunday, the Mandaean holy day.

Question: Why do they believe that?
Self-contained rewrite: Why do Mandaeans believe in the soul ceremony?