@Panzerfaust
It sounds like you are concerned about the seemingly obscure evidence for God’s existence and questioning whether the higher power explained by religion even exists. Here is the proof of your argument:
1) If God exists, then only one religion explains God’s existence.
2) If this religion exists, it should be obviously different from the other religions.
3) No single religion is obviously different from the others.
4) No single religion is obviously different from the others, so this religion doesn’t exist (MT 2, 3).
5) This religion that explains God’s existence doesn’t exist, so God doesn’t exist (MT 1, 4).
In my response, I will assume your observation that no obvious differences exist between religions is true and propose other potential explanations for the lack of obvious differences you’ve observed:
1. God does exist and is explained by one religion, like you proposed.
2. God does exist, but cannot be explained by religion.
3. God does exist and is explained by multiple religions.
4. God does not exist and cannot be explained by religion.
According to the initial premise that assumes God’s existence is explainable by religion, options one and three are the only possibilities to be concerned with because God cannot be explained by religion in the other options. However, options one and three contradict the second premise that assumes a single religion would explain God’s existence and also be obviously different from other religions. The premises are not satisfied by any of the options, so you are left with two options: 1) deny God’s existence because one religion doesn’t appear to be obviously different from other religions or 2) accept that God does exist, but is not confined to a single religion. For a more full discussion, I think the premises of your argument should be altered.