Q. How are the different laws of Leviticus characterized as civil, ceremonial, and moral? What is this characterization based on?
A. The distinction between moral, ceremonial, and civil law is often associated with John Calvin and Reformed theology, though it may go back to Thomas Aquinas in the 13th century. Some have argued that it goes all the way back to some of the early church fathers.
Biblical texts themselves do not make this distinction. In fact, there are so-called ceremonial and moral laws together in the same lists in Leviticus (in the lists in Lev 18-20, for example) without any clear differentiation, and in some cases the violations of these laws are all lumped together as “abominations.” In addition, there is nothing explicit in the New Testament to support making this threefold distinction. I would say that, in general, each of the laws points to a meaning—loyalty to Yahweh, ethical behavior in the community, and so forth—beyond the literal rule that the law contains. How one should appropriate that meaning in our world today is a difficult question and one on which modern faith communities differ.