In cultures heavily influenced by the Abrahamic traditions of Judaism, Christianity, or Islam, faith these days is practically synonymous with religion. It’s such an obvious and natural fact that we refer to all world religions as “faiths.”
So it can be hard to realize how bafflingly weird this development seemed to everyone else back then, during the post-exilic, Second Temple period. Strict monotheism and religious faith were totally new. And to the Persians, Greeks, Egyptians, Romans… they made no sense.
Even today, this particular concept of faith—a requisite belief in one’s god and in the teachings of one’s received scriptures—isn’t really a thing in most other religious traditions. About half the world’s population grew up in such cultures (even factoring in Islam’s massive baby boom that’s going on).
That’s mildly interesting, I guess. But again, so what? Faith is nothing more than thoughts inside people’s heads, after all. What’s this got to do with government and law?