There are many different approaches to moral matters in both religion and philosophy.
My personal approach is a commonsensical / realist / pragmatist's view; you can single out ethical propositions and determine which ones are senseless and which ones are reasonable, but you cannot manufacture theoretical approaches which algorithmically detect and extract undesirable features while inserting desirable features in the concepts of bad or good conduct. Human psychology / society is too irreducibly complex / variant for that, and there is nothing in natural science which suggests the world or a God is going to provide the appropriate mandate.
This is why I reject any of the popular approaches to ethics in philosophy (deontology, consequentialism, virtue ethics, etc) and the absolutism of religion (usually some kind of virtue ethics). Moreover, I feel systems like Moral Universalism, Moral Relativism, Moral Objectivism, and Moral Subjectivism are flawed, because each incorporates some facts of humanity or the world, but then starts incorporating fallacies or has only partially complete views of the facts.