The term “Sharia law” is tossed around so much these days that it could easily be mistaken for a concept that everyone understands, including non-Muslims. But that is far from the case, a fact never more apparent than when non-Muslims organize anti-Sharia protests in the name of “fighting terrorism” while simultaneously declaring their respect for “peaceful Muslims” everywhere.

Sharia, a set of guiding moral principles derived from the teachings of the Prophet Mohammed, is inseparable from the practice of Islam. Indeed, it covers every aspect of Muslim life, according to Clark Lombardi, director of Islamic legal studies at the University of Washington School of Law:

In Arabic, “Sharia” literally means “path,” and is understood to be the path to salvation. It is the sum total of the things that you must do (and refrain from doing) if you are going to heaven. This includes things that states enforce (laws against theft) and also some things that states never try to enforce — how to greet your neighbors, what to eat, how to brush your teeth etc. You answer to God for everything in the Sharia, and you only answer to the state for a few of them.

Sharia was born during a period of Islamic expansion following the death of the Prophet Muhammad in 632 AD. Its principles come from four traditional sources, writes Georgetown University Islamic civilization scholar Jonathan Brown:

The first two are believed by Muslims to be revealed by God either directly or indirectly: 1) the revelation of the Quran … and 2) the authoritative precedent of the Prophet Muhammad known as his Sunna (often communicated in reports about the Prophet’s words and deeds, called Hadith). These two sources work in tandem. The Sunna is the lens through which the Quran is read, explaining and adding to it. The second two sources are the products of human effort to understand and channel the revelation of God through the Prophet: 3) the ways that the early Muslim community applied the Quran and the Sunna, and 4) the further extension of this tradition of legal reasoning by Muslim scholars in the centuries since. The human effort to mine these sources and construct concrete, applicable rules from the abstraction of the Shariah is known as fiqh. If Shariah is the idea and ideal of God’s law, then fiqh is its earthly — and thus its inevitably fallible and diverse — manifestation.

For most of the world’s 2 billion Muslims, Sharia isn’t a list of immutable rules, but rather a body of scriptural guidelines subject to interpretation in accordance with the many schools of Islam and the different societies within which it is practiced.

“A majority of Muslims agree that reasonable people will interpret the Sharia differently,” Lombardi says:

Naturally, different countries will interpret God’s law differently. Even in areas [where] Muslim countries seem to at first glance to agree, pretty serious differences appear. For example, not all Muslim countries interpret the Sharia to permit Muslim men to take more than one wife. Of those that permit polygamy, some say that it only permits polygamy when the wife agrees. Others say that it permits polygamy unless the wife has made the husband promise at the time of marriage that he will remain monogamous.

Non-Muslims have a tendency to identify Sharia law with harsh corporal punishments such as stoning, lashings, and amputations, a category of sentences (collectively known as the Hudud) reserved for the most serious crimes in Islam (violations of the “rights of God”), including theft, illicit sexual relations, drinking intoxicants, and apostasy (renunciation of the faith).

Yet such punishments only constitute a “minuscule” portion of the law, says Brown, while the elements of Sharia covering everyday life are not that different from the Western legal tradition. Moreover, the most severe Hudud punishments are almost never carried out, traditionally, due to a competing requirement under Sharia to “maximize mercy”:

This was formulated clearly in a Hadith attributed to the Prophet that was also echoed by prominent Companions, among them his wife Aisha and the Caliphs Umar and Ali. The best attested version states, “Ward off the Hudud from the Muslims as much as you all can, and if you find a way out for the person, then let them go. For it is better for the authority to err in mercy than to err in punishment.”

From very early on, Sharia judges utilized a “near endless list of ambiguities” that functioned as an “escape hatch” from corporal punishment. Even in the few Muslim majority nations where Hudud sentences are still applied (e.g., Nigeria, Sudan, Iran, and Saudi Arabia), they are infrequently carried out:

Between 1981 and 1992, there were four executions by stoning in Saudi Arabia and forty-five amputations for theft. In a one-year sample (1982-83), out of 4,925 convictions for theft, only two hands were cut off. The rest of the guilty were punished by taʿzīr [discretionary sentencing applicable to lesser crimes]. In the same time period, out of 659 convictions for Hudud-level sexual crimes, no one was stoned. Many death sentences are the result of political punishments, not the Hudud. In Nigeria’s northern states, all of which have adopted Shariah-based legal codes, a few amputations for theft have taken place. There have been at least two sentences to death for adultery, but in all cases so far ambiguities were found to release the guilty party.

Much of the fear surrounding the so-called “encroachment” of Sharia law in Western countries — a claim Brown calls “absurd” — seems to stem from an assumption that Muslims want to impose “their way of life” on non-Muslims. But not only does this imply a monolithic sameness to Islam life everywhere, which is far from the case, it is also contrary to the tenets of Sharia itself, which, according to the web site of the Islamic Supreme Council of America (ISCA), is only meant to apply to Muslims:

If a Muslim citizen commits a religious violation, he is judged according to Islamic law. A non-Muslim citizen is judged in religious issues by the laws of his own faith.

Americans may not realize it, but jurisprudence based on religious law — Catholic, Jewish, and Islamic — is already commonplace in the U.S.

The Pew Research Center reports:

Across the United States, religious courts operate on a routine, everyday basis. The Roman Catholic Church alone has nearly 200 diocesan tribunals that handle a variety of cases, including an estimated 15,000 to 20,000 marriage annulments each year. In addition, many Orthodox Jews use rabbinical courts to obtain religious divorces, resolve business conflicts and settle other disputes with fellow Jews. Similarly, many Muslims appeal to Islamic clerics to resolve marital disputes and other disagreements with fellow Muslims.

Sharia, rabbinical, and Catholic canon law are even referenced in secular U.S. courts on occasion, albeit only in matters where the faith of the litigants is pertinent. “In the past 12 years as an attorney, I have handled many cases with an Islamic law component,” said New Jersey attorney Abed Awad in a 2011 interview with Salon:

U.S. courts are required to regularly interpret and apply foreign law — including Islamic law — to everything from the recognition of foreign divorces and custody decrees to the validity of marriages, the enforcement of money judgments, probating an Islamic will and the damages element in a commercial dispute. Sharia is relevant in a U.S. court either as a foreign law or as a source of information to understand the expectations of the parties in a dispute.

In all cases where religious law (including Sharia) is brought to bear in secular courts, U.S. law takes precedence by default.

In sum, Sharia is a faith-based code of conduct that is inseparable from the practice of Islam, yet open to interpretation, adaptable, and responsive to the needs of 2 billion adherents worldwide. Far from presenting an abstract, looming threat to American freedom, it is an integral part of the lives of the some 3.3 million Muslims who call the United States their home.