Preparing for another round of my annual course on Ancient Near Eastern Religions, I have been brushing up on Zoroastrianism. For this I generally first turn to Mary Boyce’s standard introduction, Zoroastrians: Their Religious Beliefs and Practices. The book was written in the 1980s and is showing its age a bit, but it remains a seminal introduction to a religion whose humble position among world belief systems belies its overwhelming impact. A strange fact about the religion is that many of its main tenets have been summarily dismissed by the more politically influential religions of antiquity while its secondary features have been dramatically embraced. The classic example is dualism.

Zoroastrianism was founded on a dualistic principle: Ahura Mazda was the entirely beneficent, good creator, while Angra Mainyu was the powerful principle of evil. This cosmic struggle tapped deeply into all aspects of life, leading to the beliefs in two afterlife realms (which evolve into Heaven and Hell), two very powerful entities (that become the God versus Satan paradigm), and two dispensations (present age as opposed to future age, the ultimate source of the apocalypse). Indeed, it would be difficult to recognize Christianity without Heaven and Hell, the Devil, or the final judgment. Boyce carefully traces the earliest evidence for Zoroastrianism back to its formative period and offers detailed explanations for each aspect. Beyond this, however, Zoroastrianism became a forgotten faith, an abandoned parent.

It is a fact that religions evolve. Many believers like to trust that they have the straight information directly from the founder’s mouth and that their brand is the authentic brand of faith. All religions, however, if they survive long enough, change to meet the needs of present-day adherents. Again, Zoroastrianism is instructive. Believing in the sacred nature of fire, during the industrial revolution the use of fire for profane work, such as running a steam engine, was considered inappropriate. How were Zoroastrians then to keep up with society without softening their stance on the secular use of fire? The struggle was real and has never been fully resolved. The same exercise could easily be applied to other religions as well. Until the Zoroastrian-inspired apocalypse arrives, religions will have to adjust to continual societal change and accept that quantity of belief does not affect quality.