We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.Being conservatives, we all agree that we were endowed with certain unalienable rights. But what if we were endowed by a natural process instead of a supernatural person? Does that mean we weren't really endowed with rights after all? No! We have these rights because human beings require these rights in order to survive & thrive.Definitely! That's why it's important to talk to the One who gave you the gift of reason and endowed you with certain unalienable Rights.
(Presumably) all physicists agree that matter is made up of atoms, which are themselves made up of protons, neutrons, and electrons, which are themselves made up of different combinations of quarks. This agreement is universal, even though there is great ferment & disagreement over what exactly quarks are themselves made of.
Likewise, the necessity of recognizing our individual rights comes from the fact that we are human beings, and an understanding of what it means to be human. How we came to be human instead of just another chimp, is a different question entirely, and wholly irrelevant to the more vital questions of what constitutes a proper moral framework, whether or not the best moral code is universally applicable to all people of all cultures, etc.