You do realize the same could easily be said about religion...don't you ? That it doesn't make solid sense. ...In fact, isnt that the point of "having faith"?

Fight them about it ??

....And what if Atheists or Muslims or whoever sees different from you took your attitude that others are "wrong" & as such they have the right to fight you about it?

But where/how did God come to be?

Fake?
...Have you never seen dinosaur bones?

I have always understood that Agnosticism is the belief that humans can't possible know whether there is or is not a God, & if there is what it's nature is (like whether God' s a Methodist or a Presbyterian or a Hindu or...
..or even unlike any worldly religion describes).
While Atheism is the belief there is no God(s).