I just remember how religious people fought against gay marriage as if it would ban straight marriages.

God seems to want those people be hateful people.

>anything goes, you can be whatever you feel like and there's no judgement of any of your actions.

First of all, there is judgement as soon as you actions hurt others. Beside that you can be and feel like you want.

And I remember questions like "What stops atheists from murdering people or raping kids?"

Sorry, but if the only things that prevents you from being a bad person is that you are being watched over by a higher being, then you are still a bad person.