Why atheism is irrational

[Gilgamesh]

Atheists are desperate to rationalize their atheism, and "We find insufficient evidence" makes for the perfect cover.

But how do we know if this is the reason? How do we test to see if this hypothesis is true, rather than other, non-rational hypotheses?

But you do agree that insufficient evidence does rationalise atheism, and indeed any lack of belief, correct?

You're strife is with atheists who lack belief for other reasons. If so, your original post is monstrously misleading; makes one think you're putting forward that atheism in itself is irrational.