I've never had occasion to examine the question, since I usually design campaigns to take place in a relatively focused section of the world . . .
. . . but for the last campaign setting I came up with, I can answer the question by referring to design principles.
In this setting, there were no absolutes about religion in the first place. It was shortly prior to Eberron's release, but Wizards of the Coast and I engaged in parallel evolution on the issue of non-contactable deities, even down to the question of extraplanar entities' knowing the truth of the matter.
(Eberron's answer is "They don't, but many of them believe anyway", which is slightly more sophisticated than my own of "They might and they might not, but they either can't or won't answer questions on the matter".)
I established this factor as a way of achieving the sorts of doctrinal splits we see throughout virtually every era of human history; eliminating the possibility of just asking your god which of two opposing doctrinal camps is correct leads to a more interesting and pleasing structure that
feels like the historical reality even if I have no interest in running a historical game.
What this meant, practically, was that different sects could propose radically different interpretations of the same basic cosmology, to say nothing of the conflict between those religions with wildly varying cosmological and theological ideas. For instance:
- The majority of clerics of the World Mother believe her to be the creator and sustainer of the world itself; all life proceeds from her and owes her worship.
- A minority of these clerics believe that the World Mother must have a divine consort to have brought forth life, taking the motherhood idea more literally than mainstream thought, though opinions are sharply divided on who, exactly, this consort might be.
- The clerics of another religion which proposes a Greco-Roman style pantheon of deities in some kind of "family" structure have their own goddess of the Earth, with a much-restricted sphere of influence compared to the attributes of the World Mother.
- Yet another religion devoted to the elemental forces proposes that the earth is properly associated with a masculine Elemental King, and that life is an outgrowth of the interaction of all four elements as overseen and directed by their respective Kings or Queens.
- A philosophical offshoot of this elemental religion asserts that the Elemental Kings and Queens have use only as metaphor, owning no real existence, but still subscribe to the idea that life is a mixture of all four elements.
- Several sects of druids possess different, though vaguely compatible, ideas about the World Mother in relation to the force of Nature itself which they honour: one sect might refer to the World Mother as a philosophical metaphor for Nature (as the elemental philosophers do the Kings and Queens), another might argue that the World Mother is a semi-real entity existing as a face and embodiment of Nature to which mortals can more directly relate, while a third might believe that the World Mother is a real entity created from Nature and life itself and have relatively close relations with some of the more ecumenical clerics of the World Mother.
- Other druids assert that anthropomorphising Nature is meaningless (or possibly blasphemous), revering it as an unpersonified force.
- Some folk might believe the World Mother is simply a very powerful spirit being, not truly in charge of anything per se but still disposed to use her powers on behalf of those who propitiate her with offerings and actions in defence of things she cares about.
That's just one set of examples. It's fairly simple to see how some of these points of view might simply belong to different cultures separated by geography or race (though this setting was absent playable non-human PCs).
The best answer I can give is that
ideas might be worldwide, sort of, but that specific
implementation of those ideas is a very different matter.