How to easily defeat any argument for God

[comet]

But atheists saying "we make our own meanings" does not mean "we just made it up arbitrarily yesterday."  It means we have an evolved human nature which itself determines a lot of what is good and bad for us.  It means that morality can be objective even while it is still relative to specifically human interests, as compared to the interests of mice for instance.  That's not the same as extrinsic or determined by a God.

When many atheists, particularly on the internet appeal to evolution in such discussions about morality, they rarely ever explain what they means by it here, what exactly are the features being described that are being selected for? Are you referring primarily to human behavior? Human beliefs? Our biological feelings? The biological components of our perceptions ? etc..

The atheist philosopher Alex Rosenberg provides such an explanation. He acknowledges a core morality shared universally, that people perceive as objective, but this is illusory. Our strong biological feelings and emotions produce essentially a mirage, a perception of a moral order out there, that doesn't actually exist, much like free will.

My perception of a moral law, of moral oughts and obligations, duties are perceived as objective truth, while not real, are not the product of social constructions, or religious indoctrination etc.., but strong evolutionary components, that produced a functionally useful, but false set of beliefs regarding moral foundations.

I don't find the argument convincing but at least the role of evolution here is more clearly laid out, then how ever vaguely you've used it.

In my view, evolution underpins the perception elements, that allows us to see a moral reality that is real, and not an illusion, just like it underpins the elements that allow us to perceive an objective non-moral reality outside of our minds, or the eyes that see the world around us.

most atheist believe in something.  The militant atheist would classify them as "irreligious", a title that misrepresents what atheism is as surely as Fundy theist misrepresent what theism is.

Most atheist understand that we are part of a larger more complex system.  Most even accept that "life" is a better discriptor than "non life.

atheist just do not accept an over seeing finger pointing sky wizard.  Most atheist do not need to fill in "we do not know" with said sky wizard.