Hard questions that require philosophers or priests to answer competently, and every human to make an effort. I'm only asserting that law and ethics are not synonymous: lawful evil is a box in the meme.
I understand your point that law and ethics are not same. My question is when, where, why, how and with whom do these supposedly distinct concepts originate in a world where conclusions are require incontrovertible proof and not mere belief or peddling thereof?
There will never be an objective consensus. You may only add your answers to a cacophony.
You might like to start here, for philosophers: https://plato.stanford.edu/entries/aristotle-ethics/
And here for priests: https://people.ucalgary.ca/~elsegal/TalmudMap/Mishnah/MMaim....
https://assets.cambridge.org/97805218/06558/frontmatter/9780...