Natural law does exist. Truth does exist. Perception can be faulty. Giving grace to our behaviors is comforting, but it does not annul the consequences. Truth is not invented by perspective, opinion, and culture. Conversely, whitewashing falsehood only hides wickedness; poisoned honey remains injurious no matter how sweet.
The lesson is this: ignore the popular trends that suggest spiritual laws are bygone. Trust that Truth is timeless. Without hesitation, abide first by good morals: do right by yourself in accord with nature. Then expand your morals to ethics: do right by your community in accord with the universe.
Law is absolute. The sun will always burn. That does mean I will always be burned by the sun. That does not mean I will never be burned by the sun. The consequences are relative to my actions and abilities, but the law remains the same. Whether the consequence is relatively “good” or relatively “bad,” the judgement is your choice to make, but the reality of the result is constant.
They say eating meat is good. They say eating meat is bad. Eating meat, whether deemed “good” or “bad,” is eating meat. Meat has an effect in accord with its nature.
The admonition for us is to know our nature, respect our nature, all while ignoring the temptation to think, “Nature is only an invented belief and can be abided or not to the same effect.”
To slight nature is to slight yourself. Beware, QNTN, of moral relativism.