So like, the Eastern Mediterranean especially in the time after Alexander was super religious syncretic. The Greeks didn't posit Zeus as superior to Amun due to their conquest of Egypt, they took a more practical route to integrate into the existing Egyptian systems by equating Zeus to Amun and worshipping them as the same deity.

The obvious exception were the Jews, who became a little more ethnically closed off in opposition to the polytheism around them. You start to see writers of other ethnicities like Manetho around them talk about how strange and stupid their religion was. That's kind of a proto-antisemitism.

Eventually, you had the Romans come long and conquer the whole Mediterranean but maintaining the syncretic religions as long as their subjects acknowledged the Roman Emperor as divine. This wasn't going to fly in Judaism. You see kind of an escalation where the Romans suppress Jewish religion like destroying their Temple and Jews looking towards the Romans enemies like the Persians for help in gaining their autonomy (and who doesn't want autonomy from a militaristic Empire?). Pretty soon the Jews are viewed as subsersive elements within the Empire who collaborate with the enemy, which should sound kind of familiar.