People believe in all sorts of things that may not be true.
The number of believers is not necessarily evidence for the truth of a belief.
I'd like to think that. But for sure, there is almost always some correlation between what is true in the collective mind of humanity and what is actually out there being deemed true by humans. But "true" is a human concept, not some thing that has objective existence. If 100% of people believe and agree that something is "true", then it is as true as true gets regardless of the degree of its correspondence to reality. The evidentiary basis for that belief becomes irrelevant in the absence of falsifying evidence sufficient to convince at least one person.
Science works because it eschews "truth" in favor of probability. Its highest level of certainty is "theory".
"Proof is for mathematics and alcohol".
Gods are as real as people believe them to be. My assertion would be that this makes them only negligibly "true", since far short of 100% of people agree to any given god, and the concept is totally individual. Despite endless attempts to leverage science to "prove" gods, those efforts fall short because of both the nature of science and the nature of gods.
Every individual has their own concept of god or gods. There is not only minimal agreement, one person is the max. And there is and always has been fighting over it... the utility of gods seems to be twofold: to provide solace to individuals, and to keep masses of fighting with each other.
Anyhow, iIMHO this renders gods relatively "not true",