If you think the things we misunderstand have bearing on whether or not God exist then the only alternatives left to you are to be agnostic or to base your beliefs on faith. Faithless atheism is not an option unless you know it all.
Agnosticism, as an epistemological paradigm, asserts that certain things are unknowable, and not simply unknown at the present time. If you are not sure, then you are merely that -- not sure. There simply is no sense proclaiming one's ignorance to the world and peddling it for something more than what it truly is.