Libertarianism presumes the primacy of the individual, human freedom, the right to property over nature, mankinds autonomy, a sort of equality of man, secular socialism presumes the value of each individual, the same sort of equality libertarianism presumes, it assumes concepts of justice and the rights of the commons.
On the other hand the religious presume that an imaginary, ancient, all powerful, all knowing entity, really exists for some reason. Even though there is no evidence (other than mere insufficient anecdotal ones) of such an existence. They connect such an entity with real existence not by evidence but by blind fate (i.e., willing to believe that that is so).
These are all theological claims, where do human rights come from?
From the constitution of course. It is the society that sees value in having individual rights. Not the imaginary non-existent deity above for sure.
Where does individual autonomy come from?
That is an existential given. We are alone intra and interpersonally, hence there is some vacuum between people - autonomy. Other givens are: we will die, life is meaningless unless you find meaning in them, and it is you that always decides.
Attributing and seeing the world through the religion painted glasses may be a good way to go for some. But it cannot be a good way to go for all the other reasonable people that demand evidence prior investing their beliefs.
where does human freedom come from?
Free to what extent? Define free?
Where do concepts of justice come from?
People designed them to serve a good purpose to themselves as members of the society.
The so-called secularist just assumes them.
The religious contests them.
You have so-called secularists making a God out of the Market Place, or out of Democracy, or out of a constitution, but just without calling it a God, or perhaps out of science, trying to make scientism a God and derive value judgements from science which simply do not exist in science.
You have the religious rogue political parties trying to put their imaginary entity of "God" in otherwise objective things such as: the market, democratic societies, constitution. The greatest values in religion do not even exist for they cannot come up with convincing evidence.
so called secularists want to latch on to the Legacy of Christian theology (concepts of equality, justice, individual freedom and autonomy, human rights and the innate value of man) which gave the World Things like Democracy, human rights, right to Liberty and so on, but destroy it's Foundation, but what Foundation is there in it's Place? There is none.
At the time when "concepts of equality, justice, individual freedom and autonomy, human rights and the innate value of man" were working well Christianity was not even in existence. Which brings up the fact that Christianity has borrowed these concepts from already working countries such as Greece. This would not be a problem if religion did not plagiarized history and claimed these concepts (as well as many other scientific ones) as their own.
Other concepts plagiarized from science are every possible position that the religious rogue political party has taken before and has been proven wrong from science since it was created. They include historical time (it is not thousands of years that earth existed, but millions instead. Still waiting for a BS excuse to come out of this BS religious position), the shape of the world (Earth is round, not flat!), dinosaurs existed, etc.
To make matters worse, I think since plagiarism is becoming more of a sensitive issue (people may be fined over it), while the religious still stay and do nothing but preach the same old BS, there will be other new findings from science
continuously and since it will not match with the religious BS position, you will be slowly detached from reality and become a mere myth like the rest one day.