I disagree with a lot of what you wrote, but I think the most obvious one is - this exact argument can be used to show that you must believe in the Hindu gods. Or in Islam. Or in Mormonism. Or in any of a number of other (mutually exclusive) religions.
What makes you think any particular God is the right one?
Edit: cleared up the language to make the point clearer.
What makes you think any particular God is the right one?
Edit: cleared up the language to make the point clearer.