Zoroaster

Zoroaster was born into a Bronze Age culture, which is to say, before penicillin and gluten-free toast. Details on his early life are hazy, primarily because chroniclers back then were more concerned with, well, not being eaten by sabre-toothed tigers than with accurate biographical data. He was a priest, or zaotar, who claimed to receive visions from Ahura Mazda, which sounds like a sports car but is actually the Wise Lord, the supreme being in Zoroastrianism.

His teachings, codified in the Gathas (part of the Avesta), centered on dualism: a cosmic struggle between truth and falsehood, good and evil, light and dark. This was a radical concept in its day, predating Judaism's monotheistic evolution and influencing later Abrahamic religions with ideas like heaven, hell, angels, demons, and a final judgment. Basically, he invented consequences.

Zoroastrianism flourished for centuries, becoming the state religion of several Persian empires, proving that if you preach hard enough, people will eventually listen. Even if it takes a millennium. Today, while its followers are few, its philosophical fingerprints are everywhere, making Zoroaster one of the most influential thinkers you've probably never truly studied.

In short: not a Jew, but definitely a very big deal. If you like the idea of eternal struggle between good and evil, you have him to thank. Or blame.