Shariah is the law of the Qur'an and literally means "A path to life giving water." In fact, the word Yarrah(i.e. the root of the Hebrew word Torah) means precisely the same thing. Therefore, Shariah is actually ingrained in Abrahamic tradition.
Shariah is comprised of five main branches: adab(behavior, morals and manners), ibadah (ritual worship), i'tiqadat (beliefs), mu'amalat (transactions and contracts) and 'uqubat (punishments). These branches combine to create a society based on justice, pluralism and equity for every member of that society. Furthermore, Shariah forbids that it be imposed on any unwilling person. Islam's founder, Prophet Muhammad, demonstrated that Shariah may only be applied if people willingly apply it to themselves--never through forced government implementation.
Additionally, the Qur'an does not promote any specific form of government, but requires that the form people choose must be based on adl or "absolute justice." The Qur'an says, "Verily, Allah enjoins justice, and the doing of good to others; and giving like kindred; and forbids indecency and manifest evil and transgression. He admonishes you that you may take heed" (16:91). Notice, religious preference is never mentioned. Therefore, in ruling with absolute justice, for example, the righteous Jewish King Solomon ruled as a just monarch based on this fundamental principle of Shariah Law--justice.
2. Do Muslims want Shariah to rule America?
No. Remember, the Qur'an teaches that religion must not be a matter of the state. Shariah is a personal relationship with God. Prophet Muhammad, even as the de facto ruler of Arabia, wrote the Charter of Medina in which Muslims were held to Shariah Law, and Jews to the Law of the Torah. Not a single non-Muslim was held to Shariah because Shariah itself forbids compulsion. The Qur'an clearly says, "There is no compulsion in religion" (2:257). Furthermore, Shariah obliges Muslims to be loyal to their nation of residence. Therefore, American Muslims must adhere to the US Constitution as the supreme law of the land.
3. If Muslims don't want Shariah to rule America, then so what if it's banned?
First, Shariah is a personal relationship between a Muslim and God. The First Amendment forbids Congress from passing laws that restrict the free exercise of religion--particularly private exercise. Second, if Shariah was banned, then American Muslims could not marry, inherit, write wills or choose to divorce per Islam's guidelines. If similar restrictions were imposed for other faith groups, then no Minister could conduct a marriage ceremony, no Catholic Bishop could read the last rites and no Rabbi could perform circumcision on an infant male Jewish child--because these are all Judeo-Christian religious laws. Even within our current legal system, American Jews regularly resolve civil matters through rabbinical courts known as beit din. American Muslims simply want to enjoy their same constitutionally guaranteed right.
4. What does Shariah say about other religions?
Shariah law champions absolute freedom of conscience and freedom of religion. For example, the Qur'an goes as far as to oblige Muslims to fight on behalf of Jews, Christians and people of other faiths and to protect their churches, synagogues and temples from attack. (22:41) Furthermore, Shariah holds that to be a Muslim, a person must testify to the truth of all past prophets, including Jesus, Moses, Abraham, Krishna and Buddha--and must respect their adherents. When Prophet Muhammad peacefully became the ruler of Arabia, his primary condition for non-Muslims (and Muslims) to reside in Arabia was that they allow all people of all faiths--be they Jews, Christians, Muslims or idol worshipers--to worship in peace and without oppression.
5. What about countries that oppress people and claim they follow Shariah?
Such countries have ignored the fundamental tenet of justice inherent in Shariah Law, and have instead used Shariah as an excuse to gain power and sanction religious extremism. To be sure, not a single example of a "Shariah compliant" country exists. In fact, the most "Muslim country" in the world is likely America, because America guarantees freedom of religion, freedom of speech, freedom of expression and freedom of thought--all hallmarks of Shariah Law. Those nations that oppress in the name of Shariah are as justified in their claims, as the slave owners who claimed their right to slavery was based on the Bible.
As for the "violent" verses from the Qur'an that are cited by both extremists and critics--honest legal interpretation abhors quoting an excerpt as a means to understand the full law. Unfortunately, both extremists and critics refuse to adhere to this basic principle. In sum, Shariah law guides a Muslim's personal relationship with God, just as the Old and New Testaments guide Jews and Christians in their personal relationships with God. These paths to life-giving water are nothing to fear.