Christians take on the more nihilistic atheists

[Brakeman]

I don't believe humans make choices.  

WTF?? That's silly. Of course we make choices. You made a choice to respond to my text and you used your morality to temper your textural response. Morals do not have to be big issue like murder, theft, or adultery. It can be as small as agreeing on forum standards and abiding by forum rules.

That being said, I think humans follow the morality they make up in the same way humans follow the God they make up.  

So the distinction is the notions of morality, God, and unicorns exist, but morality, God, and unicorns don't actually exist.
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Either way, I find the idea of morality, subjective and objective, as irrational nonsense.

mo·ral·i·ty
məˈralədē/
noun: morality

   principles concerning the distinction between right and wrong or good and bad behavior.

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Behavioral principles are certainly not irrational. Objective morality as exemplified by commandments from gods or claimed as natural laws are irrational and this is the basis for the Subjective vs Objective morals debates.