Although man’s law when built on God’s law is objective.
Absolutely true. You will always have different interpretations, and as we have seen through history, some people are willing to kill over their interpretation.
That’s what makes what the founders did so amazing. For the first time in human history a government was formed that did not have an official religion. In fact, it states explicitly in the constitution that there will be no religious test for public office.
Though of course most of the founding fathers were some denomination of Christianity.