It is an immensely difficult question, and as is so often the case, religion will play an important part. Too often, sadly, a harmful part.
I can only speak from my own perspective on this, as a Humanist, a liberal democrat with a social conscience, and most importantly, as one who believes that governments are human constructions to enable us to get things done that are beyond the capacities of individuals or small communities. Governments, most importantly, should govern, not rule. Humans do not need to be ruled, but they do often need to cooperate at levels that our evolution on the African savannah does not really equip us for.
As I humanist, I believe that all humans (barring blatantly anti-social behaviours) are of equal value. Not "equal" -- no philosophy can make us that, as we all have our individual capabilities and weaknesses, desires and dislikes, and so on. But we are of equal value. If I believe that, I can only believe that every human has some of the same essential needs that I wish for myself: life, liberty, the right to pursue my own ends and satisfactions. I also believe that, as a social species, all humans have a duty to at least not deprive other humans of those same things -- in other words, to do no harm.
From that, I understand what the UDHR is all about. It recognizes that we are different, that we have, as I said, our individual capabilities and weaknesses, desires and dislikes, etc. But it attempts to enshrine our right to be free from interference -- especially by governments (I don't recognize "rulers") in the pursuit of our individual ends -- so long as we do not harm others.
Women are as fully human as men, and therefore must be enable to pursue education, their own liberty, participation in elections, the jobs they want, and so on. Gay people are as fully human as straight people, and everyone should have the right to pursue that area of their happiness and satisfaction, too -- so long as we do not harm. Gay or straight, it must be wrong to act sexually against anyone's will, for example, but it must also be right for two persons (of any gender) to enter into the relationships that a society recognizes (that may be marriage of two persons, or more), with the same rights and responsibilities afforded by the society.
For me, these things are not given by God, or granted by state or universal charters, but are ours by the very nature of our being human. No human born, for example, can possibly be considered the property of any other human -- humans are neither crops nor livestock. And if they cannot at birth, then they cannot then be slaves, except at their own express consent, and for only so long as that consent continues to be given, at any other time in their lives.
This is what Humanism, and my own philosophy, teaches me: that I can know right from wrong without having been taught or commanded, through nothing other than my recognition of my humanity in the company of humans, and through my reason considering what I've written above.