I'd argue that the moral principles of the Levitical law (e.g. "adultery is wrong") are not inherently bound to the specific punishments (e.g. "adultery is a capital crime") prescribed for ancient Israel.
To defend against the accusation of cherrypicking: I don't actually think the original punishments were objectively morally wrong (even though they certainly feel harsh to my modern sensibilities)βsin is no joke. At the same time, I also don't believe that the punishments (or even all of the crimes, i.e. the liturgical ones) were intended to apply to all polities throughout history. Admittedly, my argument would be primarily theological in nature[1], so I don't expect it to be convincing... we may have to agree to disagree :-P
[1] Namely, "ancient Israel is the only divinely instituted theocracy in history, so many things just won't generalize to more 'normal' polities". And/or, see Jesus' treatment of the Mosaic Law in the gospels (and the New Testament more generally).
