Do we support freedom of religion and nonestablishment of religion out of convenience, or on principle?

In response to my post about whether Tunisians will embrace a secular constitution or not, a friend wrote and asked whether I thought that the process of Christians embracing freedom of religion and separation of “church” and “state” was just motivated by convenience (things would “work better”), or whether such a commitment is actually rooted in Christian teaching?

My conviction is that the teachings of the Bible and the example of Jesus inherently support freedom of religion and nonestablishment (especially, not using establishment of religion to persecute others who differ in belief or practice, whether other Christians, or people of other religions or none).

I would point to the fact that the Bible teaches that God has given men and women the responsibility and the freedom to respond to him (or not), and that we are not to judge others, but to leave judgment to God; and that Jesus taught that his “kingdom” was not a political kingdom (e.g., a political alternative to Roman rule), but was of a different nature, meant to work (as leaven, in one of his parables) within existing social structures (of any kind).

It is my understanding from reading Christian history, that there has been a progression both in thinking about how to best live together in society with others of different faith (Christian and other), from a practical standpoint, and in (re)thinking about Biblical perspectives  on the relationship of “church” and “state,” on a level of foundational principles. I don’t know of anyone advocating that Biblical teaching would encourage Christians to seek to return to an establishment of religion or an abolishing of freedom of religion (though there are those calling for a return to America as a “Christian nation,” and there is what I see as a natural tendency for any group of people to want to have their own beliefs and practices and social standing, protected from or by the government – i.e., a group self-centeredness, which might lead Christians to act as if they did not think that the Bible’s teaching would lead us to stand up for freedom of religion for all people, not just for ourselves).

Jesus taught that we should “love our neighbor as ourselves,” and that we should “do unto others as we would have them do unto us.” Both of these teachings, I would argue, should lead us as followers of Jesus (or “Christians,” if you will) to stand for freedom of religion for all, and for nonestablishment of religion for all, for the sake of us all.

My question, then, to followers of other religious teachings would be: am I right in thinking that your faith would lead you to stand for the same freedom for all, and disestablishment of the religion of one particular group, for the sake of equal rights for all?