In the United States it is the majority opinion (vocally, anyway) that God is a real thing with both interest and power to intervene in both historical and day-to-day events.
As to why? A lifetime of indoctrination and social pressure. The same reason anyone believes anything, I suppose.
Your previous statement might be true - and also has nothing to do with a "universal reference frame".
A god that intervenes has nothing to do with whether or not the God is physical.
I suspect you are reading things into what people believe without actually understanding what they believe. i.e. that it's actually you that believes God has a reference frame, not that the majority of people in the US do.
Well, I'm not that interested in the theology of an interventionist God because it's not a very exciting fairy tale to me. But as I understand it God is omnipresent and omnipotent and either those things mean a physical presence that is everywhere at once or they mean nothing at all. That is precisely the thing proscribed by relativity.
I'm sure one could define God down into some kind of good-vibes field that could logically exist in our universe, and that's all good with me. But it's not what most Americans profess to believe. In any event, discard it if it offends you; it's completely irrelevant to the topic, which is super-cool physics.
> mean a physical presence that is everywhere at once
Everywhere at once means "no privileged reference frame". (Kind of like how light, from the point of view of light itself is everywhere at once, and light also has a the special privileged reference frame of no reference frame at all.)
You were the one who claimed the most people believe in a privileged reference frame based on God. Not me. Now you are backpedaling from that claim - which is fine, because not only do most people not believe that, it doesn't even make any sense.
And I agree that this should conclude the religious digression of the main topic. Not that there is a whole lot more to talk about, unless you want to talk about (argue with?) my comment above on light.
> Everywhere at once means "no privileged reference frame".
Probably you'll never read this now, but... Nope. Everywhere at once literally means a privileged reference frame. "Over there, now" is a concept with no logical meaning in our physical universe. Being in two places at once isn't physically impossible, it's just nothing.
And that imposes very serious constraints on God. If I am on the Earth and I pray for my husband on Mars, God on Mars can not hear my prayer until it is too late. You really think that's a statement most Americans agree with?
You're also off about light. Light is not "everywhere at once from its own perspective" as you seem to think. The fact that light cannot be everywhere at once is the same fact that dictates that light cannot have a point of view, that light experiences no time and has no perspective. (Mind you, if this is the comparison you would like to draw to God, I will happily assent.) Study up and be a bit more careful with your science, and you'll be able to throw much meatier punches theologically.
As to why? A lifetime of indoctrination and social pressure. The same reason anyone believes anything, I suppose.