Human rights do not have adequate justification under a secular government.

Thanks for accepting. A right is unalienable, and granted to one by an authority, and held by the one to whom it is granted until they no longer hold the position they came to which entitled them to the right. In this case, the rights we are granted are human rights, so as long as we are humans, we have these rights. It is clear from the Declaration of independence that rights were held as endowment from God by it's signers: “When in the Course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. 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. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed...” I have reservations about the “pursuit of happiness” bit, but that's another story. Why must rights be granted by an authority? If a single person publicly declares they have a right, it wouldn't be much noticed unless it was a right that impeded someone else's desired goals. And such a person who disagreed might not take the declarer as a serious threat unless they thought that the declarer could back up their claim with the force of some kind of authority. The force the declarer could use to back up the claim of a right could be as simple as physical or psychological intimidation, one-on-one, or from a group or mob. Force by itself can be a form of authority. The silver-back and the alpha use nothing but intimidation and force, and they are authorities in their societies. Peer pressure, guilt, bribery, or even convincing reason could be used to back up the person declaring their right. But as I said at first, without any of these authoritative mechanisms, the declarer of the right doesn't have much of a way to get what they want. Why must God be the authority that grants human rights? Rights can be granted by human authority alone, but only as long as the human authority can maintain that authority. And individual humans generally have a quick expiration date when compared to societies. That's why we like constitutions, charters, and laws that go beyond our lifetimes, to lend more stability than an absolute dictator alone could provide. But laws that can be changed by legislatures, oligarchies, kings, and popular vote can also be fickle. Laws can even remain on the books, but be unenforced by the people who are charged with enforcing them. For roughly 6-10k years of human history, the essential nature of humanity has not changed. We are still essentially human, and as long as we maintain that status, we would have human rights if they existed at all. Who else could grant those rights but an immortal, unchanging God who has communicated those rights to us?