>>17766264 (OP)There are a few things to say about this.
The Old Gods were basically dead at the time.
Platonism and traditional Greco-Roman religious ideas pushed heavily for a universalism of deities. Romans loved importing new savior Gods.
Traditional Greco-Roman religion mostly scaled in its 'effectiveness' with your economic power. The poor had less ability to commune with the Gods than the rich did.
Rome was in an unstable period.
Jews were just another weird group of people that the Romans knew among many weird groups of people.
You can read very mainstream works like Pliny's History and see how Romans, especially those in the upper class, but ostensibly spreading down some, really didn't take their religion that seriously as dogma.
Pliny makes fun of the masses for worshiping too many Gods and mostly assumes a type of pseudo-monotheism where he talks about the divinity in the singular, but also acknowledges some larger and more important divine forces. Your classic Hesiodic gods were discounted pretty significantly in this system, or abstracted away into metaphors.
Pliny wasn't a theologian, so this demonstrates that the view was probably fairly common among the upper classes at the very least.
This comes from a long line of Platonic and Stoic philosophers that generally viewed more traditional Greco-Roman religion with derision or as mere metaphor and abstract representation of natural forces.
Apollo literally wasn't the god of the sun, instead he was a metaphor for the celestial and natural forces embodied by the sun.
This connects to a Roman perception of deities as all being fundamentally the same between civilizations.
Your God is the same as my God is the same as our neighbor's God. So long as the subject they covered was similar. Even if we call them by different names or worship them in at least slightly different ways.