On Religious Freedom

The issue of religious freedom has been brought up in regards to the issue of the mosque that is planned for construction at Ground Zero in New York. Some have made the argument that the construction of the mosque should be allowed because in America, people are free to worship as they see fit.
Is this argument valid? The Imam behind the planning of the mosque is being deliberately provocative, wanting to use the mosque not just as a center of worship, but also as a means to introduce Muslim law to America. This casts doubt on the idea that the construction of this mosque is merely religious. But another to look at this issue is to consider: what is the extent of religious freedom?
As an extreme example, suppose there was a cult whose worship practices included murdering a victim to make a human sacrifice. Would such as cult practice be acceptable as a matter of religious freedom in the United States? I would say it most definitely shouldn’t. The taking of a human life in such a manner is unacceptable, even if it is claimed to be a ritual of a religion.
But hang on. Why is the taking of a human life (in other words, murder) wrong? Most people would agree that murder is wrong. They may say that it violates God’s Laws, they may say it deprives the victim of freedom, they may even argue it decreases the reproductive potential of the human species. There may be different reasons given for why murder is wrong, but all these reasons have something in common: they are derived from a person’s worldview. A person may regard God, freedom, or reproductive potential as the ultimate standard or authority in determining moral issues, but regardless, an ultimate authority does exist.
Here comes the catch: acknowledging an ultimate authority signifies a religious view. In other words, any reason for judging murder to be wrong would be founded in a religion. (Some people may have a hard time accepting libertarianism and evolutionism as religions, but if these ideologies are not religions themselves, they are certainly derived from the religion of humanism.) So the result is that one religion (which views murder as wrong) ends up banning the practice of another religion (the hypothetical cult). The conclusion of the matter should be that while there is a separation between church and state (a separation of a specific body of believers and the civil governing body), there can be separation of religion and state, for in order for a state to enact laws (in other words, decree something to be right or wrong) it must appeal to some ultimate authority (a religion).
How does this apply to a mosque being built on Ground Zero? Ground Zero is a reminder of the capabilities of Muslim terrorists. The Imam behind the mosque proposed for Ground Zero knows this and is being deliberately provocative in setting up a Muslim place of worship where 3,000 Americans were murdered by Muslim terrorists. There are those who may want to distinguish between moderate Muslims and extremist Muslims. However, consider that: do we want Sharia law practiced in America? From what I know, Sharia law is derived from Islamic teaching. Some moderate Muslims may say that it isn’t or that there is disagreement as to the particulars of the law, but that only leads to a further question: will moderate Muslims whose morality mimics Christian ethics (the ethics that our nation was founded on) be the face of Muslims in America, or will be Muslims who espouse all parts of Sharia law? Unless we want to exchange the religion our government was (and still is, in many ways) founded on for Sharia law, we must be careful about mosques and Imams and the things they symbolize and teach.