As much as religion’s defenders would like us to believe otherwise, there is no non-human moral authority. Every religious text in the world was written, edited, translated, and printed by humans.
All edicts, interpretations, decrees, proclamations and fatwas issued by churches are human opinions. If a huge, glowing set of tablets with commandments engraved on them descended from the sky accompanied by angels blowing trumpets, we’d be having a very different debate, but there is no such thing.
All moral opinions come to us from human beings. The only question is whose opinions we should accept as normative, and why.