JetLeg,
Please don't take this the wrong way, but you need to brush up on your logic skills.
The majority of people in the world does believe in an immaterial god.
Define "immaterial." You seem to be confusing "immaterial" and "inconsequential." An immaterial god who is consequential can still affect and communicate with the world, and therefore there may be evidence of such a god. So I'm not sure what being immaterial has to do with anything at all.
Of course, the fact that there
may be evidence of a god doesn't necessarily mean that there
is evidence. For example, the god might be all-powerful and choose not to leave any evidence.
The majority of the people in the world believe in a consequential god that is capable of being immaterial or of appearing materially at will. Therefore, if your god is inconsequential as you previously stated, or if it cannot appear materially as you previously stated, then the majority of people in the world believe in gods that are quite different from yours.
I would not use this argument to prove falsifiable things. The majority of humanity can believe that the earth is flat, but it is falsifiable.
At one time, the belief that the earth is flat was unfalsifiable, because it was (at the time) impossible to prove false (that's what unfalsifiable means). Whether a god exists or not is also currently unfalsifiable, but might be falsifiable at some point in the future, or might even be verified as true or false.
Falsifiable or not, the number of people that believe a particular proposition has no bearing whatsoever on whether that proposition is true. This fallacy has been pointed out to you several times. Even if it was true, the argument wouldn't hold for the god you described since it is quite different from any god that a majority of people believe in.
I do think that if the majority of humanity believes in something which is unfalsifiable, it must be true.
If something is unfalsifiable, then by definition it
may be true, but may not be true. The number of people who believe it is irrelevant to whether or not it is true. In addition, things that are unfalsifiable today may be falsifiable tomorrow.
-Bri