Nothing natural here. Either you are a believer and then the ‘Rights of Man’ derive from “God created man in his own image” (KJV, 1:27, probably the most important contribution Christianity made to the welfare of the humankind) or you don’t and then you are wise enough as to understand that the communities/nations that applied this concept have fared better in times past and have a lot better chance of surviving whatever the future will throw at them than the rest of them.
Rivers of ink may be used to discuss the matter but the facts are simple. The entire history of man is the history of the individual becoming more and more autonomous by building stronger and stronger ties with the rest of the society. This may sound paradoxically but it isn’t as I’ll try to convince you in the coming days.
If you don’t have enough patience you may read ‘Starship Troopers’ by Robert Heinlein for a more convoluted version of the same argument.