It's generally agreed upon in our culture that religious freedom is a good thing. I don't know of many people walking around waving signs saying, "Down With Religious Freedom! Repeal the First Amendment!" Right or Left, we all recognize (at least in theory) that religious freedom is a noble principle that ought to be a part of our society
So, if all governments are, at least in that sense, religious how then can we have religious freedom? Well, it depends on whether the religion governing the land is one that professes salvation through faith or salvation through works. Because works are external actions they can forced up the citizenry. But faith is, by it's very nature, a free, voluntary, internal act. If faith is forced is ceases to be faith.
So, when a works-based religion gains hold over a government, religious freedom dies. Islam, for example, is a works-based religion. You can force people to utter the words, "There is one God and Mohammad is his prophet". Men can be made through coercion to practice the five pillars. If works can be forced than salvation by works can be forced as well. Thus, it's only logical for Islamist governments to bring people into salvation, by the sword if necessary. The Arab Spring is proving that the Islamist mindset cannot produce freedom of religion.
But Biblical Christianity is a faith-based religion. Men cannot be forced into having their hearts changed. They cannot be made by the sword to put their faith in Jesus Christ. Thus, a truly Christian government will not force people to become Christians, for that would ruin the whole point. A biblical State will protect the rights of non-Christians to freely and publicly worship; not because all religions are equally valid but because the State is simply not qualified to make disciples. That is to be done by churches and individual Christians, not by men in dark suits. Thus, a society can only have religious freedom if it understands the Christian Gospel of salvation by grace through faith.
Now, this is the part where someone raises their hand and says, "Um, Josh, I think you need to take world history again. Many Christian governments persecuted unbelievers."
That's only too true. I've been to Lima, Peru, and seen the old Inquisition there, complete with grotesque wax statues of tortured "heretics". It's tragically true that elements of Christendom have opposed religious freedom. But just because a nation has a crucifix on their flag doesn't mean they understand the Gospel. Just like pilgrimages to Mecca can be imposed by the State, so can baptism and saying "hail Mary". Every "Christian" government that has opposed religious freedom was operating from a gospel that had been, in some way, perverted. But if a culture does understand the Gospel it will secure religious rights for all. Therefore, it is not in opposition to religious freedom, but in defense of it, that we must be bold to spread the Gospel of our Lord Jesus Christ.
Right now, the United States is governed by the Cult of Tolerance. It's is a functional religion with a functional gospel. "Tolerate and be saved." Does this religion allow for religious freedom? Increasingly, we are discovering that the answer is "no". Pastor Louie Giglio was originally supposed to give the benediction at President Obama's inauguration yesterday. However, he was dismissed after a sermon he preached against homosexuality came to light. On the one hand, I don't have a problem with this. It's Obama's gig and he can have whoever he wants give the benediction.
Thus, may we protect religious freedom for all by insisting on the exclusiveness of Jesus Christ.