Morality and "law" clash because "laws" are inherently immoral. "Laws" are just wishes of ruling class, and at best they are merely a prescription for severity of punishment for deviating from will of the ruling class.
"Law" is not a moral guidance. And IMHO the biggest problem with conflict between one's moral judgement and "laws" is this:
Must the citizen ever for a moment, or in the least degree, resign his conscience to the legislator?
-- Henry David Thoreau, "Civil Disobedience" 1849
FYI: The main problem with the world and the solution