From an astute correspondent:
So we come back to the concept of Sharia, which you rightly mentioned in one of your posts. This is really the thing where Islam stands out from other religions, the idea that religious belief should be the basis of law. Here I found Islamic Law: The Sharia from Muhammad's Time to the Present (Hunt Janin, André Kahlmeyer) useful. The concept of Sharia is essential to Islamic belief. See Sura 33:35—36. Islam means ‘submission’: the primary duty of human beings is to submit totally to the will of God. The sharia shows the faithful how this submission should be put into practice in daily life.
[The sharia] does not grow out of, and is not moulded by, society as is the case with Western systems. Human thought, unaided, cannot discern the true values and standards of conduct; such knowledge can only he attained through divine revelation, and acts are good or evil exclusively because God has attributed this quality to them. In the Islamic concept, law precedes and moulds society; to its eternally valid dictates the structure of State and society must, ideally, conform.
Notwithstanding the great outpouring of books and articles which have appeared in the wake of the 11 September 2001 terrorist attacks on New York and Washington, D.C., the Islamic world is still not understood in the West today. The sharia is, beyond any question, one of the most important concepts of Islam, but most non-Muslims know almost nothing about it.
I wholly endorse the foregoing as an understanding of Islam. Islam is a hybrid ideology: both a religion and a political system. Sharia, or Islamic law, is essential to it. Coming from God, it cannot be questioned by man: man must submit to it. The primary meaning of 'Islam' is submission. God's law must be imposed on all and woven into the fabric of everyday life. There is no provision in Islam for mosque-state separation. But that is to put it in the form of an understatement. Islam positively rules out mosque-state separation.
John Hick, An Interpretation of Religion (Yale UP, 1989, pp. 48-49):
From the point of view of the understanding of this state of islam [submission to Allah] the Muslim sees no distinction between the religious and the secular. The whole of life is to be lived in the presence of Allah and is the sphere of God's absolute claim and limitless compassion and mercy. And so islam, God-centredness, is not only an inner submission to the sole Lord of the universe but also a pattern of corporate life in accordance with God's will. It involves both salat, worship, and falah, the good embodied in behaviour. Through the five appointed moments of prayer each day is linked to God. Indeed almost any activity may be begun with Bismillah ('in the name of Allah'); and plans and hopes for the future are qualified by Inshallah ('if Allah wills'). Thus life is constantly punctuated by the remembrance of God. It is a symptom of this that almsgiving ranks with prayer, fasting, pilgrimage and confession of faith as one of the five 'pillars' of Islam. Within this holistic conception the 'secular' spheres of politics, government, law, commerce, science and the arts all come within the scope of religious obedience.
What Hick calls a "holistic conception," I would call totalitarian. Islam is totalitarian in a two-fold sense. It aims to regulate every aspect and every moment of the individual believer's life. (And if you are not a believer, you must either convert or accept dhimmitude.) But it is also totalitarian in a corporate sense in that it aims to control every aspect of society in all its spheres, just as Hick points out supra.
Islam, therefore, is profoundly at odds with the values of the West. For we in the West, whether (old-time) liberals or conservatives, accept church(mosque)-state separation. We no doubt argue heatedly over what exactly it entails, but we are agreed on the main principle. I regularly criticize the shysters of the ACLU for their extremist positions on this question; but I agree with them that "Congress shall make no law respecting an establishment of religion . . . ." This implies that the government shall not impose any religion upon the people as the state religion.
This raises a very serious question. Is Islam -- pure, unEnlightened, un-watered-down, fundamentalist, theocratic Islam -- deserving of First Amendment protection? We read in the First Amendment that Congress shall not prohibit the free exercise of religion. Should that be understood to mean that the Federal government shall not prohibit the establishment and free exercise of a totalitarian, fundamentalist theocratic religion in a particular state, say Michigan?
The USA is a Christian nation with a secular government. Suppose there was a religion whose aim was to subvert our secular government. Does commitment to freedom of religion enjoin toleration of such a religion?
Obviously not! Sharia is essential to true Islam. But Sharia is subversive of our system of government. So we are under no obligation from the Constitution to tolerate Sharia-based Islam. The Constitution is not a suicide pact. This implies that Muslims who do not renounce Sharia should not be eligible for positions in the government.
"But this violates Article VI of the Constitution!" No it doesn't. There we read that "no religious Test shall ever be required as a Qualification to any Office or public Trust under the United States." But this cannot possibly be interpreted in such a way as to allow into the government elements subversive of the system of government the Constitution defines.
Why is Islam incompatible with the West? It is because Islam violates the separation of the religious and secular spheres. But why should they be kept apart? One reason is that we in the West have come to realize over the centuries that no one can legitimately claim to know the answers to the Big Questions about God, the soul, the purpose of human existence, the nature of the good, and so on. Only if one were absolutely certain of the answers to these questions would one be justified in imposing them via state power on everyone and forcing everyone to live in accordance with them. If we know that the Bible is the inerrant word of God and that God has condemned sodomy, and sanctioned the killing of sodomites, then we would perhaps be justified in outlawing sodomy and punishing it by death as it is indeed punished in some ten Muslim countries.
But surely no one of us KNOWS that God exists, let alone that God has revealed himself to man, let alone in a particular book or set of books, let alone inerrantly. Not knowing these things we have a good reason to tolerate homosexual and heterosexual sodomites, subject to certain restrictions, e.g. 'between consenting adults,' etc. We have reason to allow such behavior as legally permissible even if it in fact morally impermissible. For again, even if sodomy is is in fact morally impermissible because condemned by God , no one can legitimately claim to KNOW that it is.