An atheist claims "there is no God" or that eg "there is no Christian God".
But the atheist made a fatal mistake here: he mistook absence of evidence with evidence of absence.
This is such a grade school mistake that it kinda makes every atheist look stupid.
If anything religion is more rational than atheism because a relgious persons "belives" and a belief has a less severe requirement to be logicaly sound than atheism (since a belief is subjective).
That is because if you claim "there is no God" the burden of proof is on you to present the evidence, and yet no atheist has any evidence for that.
So in the end neither theists nor atheists have any solid proof for or against it.
But since belief is subjective it has less epistemological requirements than an atheist claiming "there is no God".