This misconception is one of the most widely held misconceptions about Islam today. And yet in the Qur'an, the Creator unambiguously states (translation),
[17:33] Nor take life - which Allah has made sacred - except for just cause. And if anyone is slain wrongfully, we have given his heir authority (to demand retaliation or to forgive): but let him not exceed bounds in the matter of taking life, for he is helped (by the Law)
Based on this verse, it is Islamically unlawful to murder anyone who is innocent of certain crimes. It is well to remember at this point the distinction made above between Qur'an and Sunnah, and the Muslims: only the Qur'an and Sunnah are guaranteed to be in accordance with what the Creator desires, whereas the Muslims may possibly deviate. Hence, if any Muslim kills an innocent person, that Muslim has committed a grave sin, and certainly the action cannot be claimed to have been done "in the name of Islam."
It should be clear, then, that "Muslim terrorist" is almost an oxymoron: by killing innocent people, a Muslim is commiting an awesome sin, and Allah is Justice personified. This phrase is offensive and demeaning of Islam, and it should be avoided. It is hoped that as the general level of public awareness and understanding of Islam increases, people will keep "terrorism" and "Islam" separate from each other, not to be used in the same phrase.
Another reason advanced in support of the misconception is that the Creator has imposed `jihad' on us. The term "holy war" is from the time of the Crusades and originated in Europe as a rallying cry against the Muslims in Jerusalem. Jihad is an Arabic word meaning struggle, but in the context of many verses in the Qur'an, it carries the meaning of military struggle, or war. Allah gradually introduced the obligation of military struggle to the Muslim community at the time of the Messenger (saas). The first verse ever revealed in that connection is as follows (translation),
[22:39] Permission (to fight) is given to those upon whom war is made because they are oppressed, and most surely Allah is well able to assist them;
This verse lays down the precondition for all war in Islam: there must exist certain oppressive conditions on the people. The Creator unequivocally orders us to fight oppression and persecution, even at the expense of bloodshed as the following verse shows (translation),
[2:190-192] And fight in the cause of Allah with those who fight with you, and do not exceed the limits, surely Allah does not love those who exceed the limits. And kill them wherever you find them, and drive them out from where they drove you out, and persecution is severer than slaughter, and do not fight with them at the Sacred Mosque (in Makkah) until they fight with you in it, but if they do fight you, then slay them; such is the reward of the unbelievers. But if they desist, then surely Allah is Forgiving, Merciful. And fight with them until there is no persecution, and religion should be only for Allah, but if they desist, then there should be no hostility except against the oppressors.
As one might imagine, the method of military struggle has been clearly and extensively defined in the Qur'an and Sunnah. Since this subject is a huge one, we simply summarize part of it by noting that it is unlawful to kill women, children, the infirm, the old, and the innocent. From the Sunnah, specifically in the study of the Sunnah called Sahih Bukhari, we find:
[4:52:257] Narrated 'Abdullah: During some of the Ghazawat of the Prophet a woman was found killed. Allah's Apostle disapproved the killing of women and children.
A related misconception to jihad is often propagated by Muslims who say that "Jihad is only for self-defense of physical borders." The Qur'an and Sunnah refute this notion categorically. As the verses cited above show, jihad is obligatory wherever there is injustice, and Muslims need not acknowledge imaginary lines around the earth when it comes to upholding this obligation. The Messenger of Allah (saas) has also commented on this extensively in the Sunnah. From the study of the Sunnah called Sahih Bukhari, we find that,
[4:52:65] Narrated Abu Musa: A man came to the Prophet and asked, "A man fights for war booty; another fights for fame and a third fights for showing off; which of them fights in Allah's Cause?" The Prophet said, "He who fights that Allah's Word (i.e. Islam) should be superior, fights in Allah's Cause."
Hence, the Creator obligates us to fight wherever people are being grossly deprived of freely hearing or practicing the Message of Allah as contained in the Qur'an and Sunnah. Sayyed Qutb, a famous Muslim scholar eloquently discusses the notion of jihad and self-defense in his book Milestones,
"If we insist on calling Islamic jihad a defensive movement, then we must change the meaning of the word `defense' and mean by it `defense of man' against all those elements which limit his freedom. These elements take the form of beliefs and concepts, as well as of political systems, based on economic, racial, or class distinction."
A third reason often cited for the misconception about Islam which says that this way of life tolerates the killing of innocents is that the judicial system of Islam is unnecessarily harsh. This reason is weak in two respects. First, it presupposes that human beings are more just and more merciful than the Creator, and therefore we can change the law. Second, it is often based on gross oversimplifications of Islamic law, such as saying "all thieves get their hands cut off."
The Qur'an and Sunnah make it clear that the law of retaliation (or equality) governs us for murder and physical injury, but forgiveness is better as the following verses from the Qur'an show (translation),
[2:178] O you who believe! the law of equality is prescribed to you in cases of murder: the free for the free, the slave for the slave, the woman for the woman. But if any remission is made by the brother of the slain, then prosecution (for the bloodwit) should be made according to usage, and payment should be made to him in a good manner; this is an alleviation from your Lord and a mercy; so whoever exceeds the limit after this he shall have a painful chastisement.
[42:40-43] The recompense for an injury is an injury equal thereto (in degree): but if a person forgives and makes reconciliation, his reward is due from Allah: for (Allah) loves not those who do wrong. But indeed if any do help and defend themselves after a wrong (done) to them, against such there is no cause of blame. The blame is only against those who oppress men and insolently transgress beyond bounds through the land, defying right and justice: for such there will be a grievous penalty. And whoever is patient and forgiving, these most surely are actions due to courage.
The Creator ordained the law of retaliation on us knowing full well that we might question it. In many non-Muslim societies today, there are ongoing debates about the death penalty. In Islam, this discussion is moot: the Creator has decided the matter for us. He has however given us an interesting verse in the Qur'an which advises to consider the matter carefully if we want to understand it (translation follows),
[2:179] And there is life for you in (the law of) retaliation, O people of understanding, that you may guard yourselves.
Most people are also unaware of the stringent conditions which must be met for the law of retaliation to be applicable. The Sunnah is full of examples of the Messenger of Allah showing us when the law's preconditions were fulfilled. For example, a thief is only liable to lose his or her hand if the item stolen exceeds a certain value, and if it is proven that the item was taken from its normal resting place. Stealing food is not punishable by the loss of one's hand, and other items are exempt as well. This is just an example of how gingerly the law is applied in Islam.
Finally, another reason advanced for this prevalent misconception is that Islam `spread by the sword'. It should be clear by now that we must always distinguish between the Qur'an and Sunnah and the Muslims when it comes to determining what the Creator has asked of us. Allah has stated clearly in the Qur'an (translation),
[2:256] There is no compulsion in religion; truly the right way has become clearly distinct from error; therefore, whoever rejects Satan (and what he calls to) and believes in Allah, he indeed has laid hold on the firmest handhold, which shall not break off, and Allah is Hearing, Knowing.
Hence, it is impossible to accept Islam under duress. Even if misguided Muslims were to try to `force' Islam somehow on others, it would not be accepted by the Creator based on this verse.
Historical arguments that try to demonstrate that Muslims did not `convert others by force' are actually secondary to the argument given above. However, it is worth noting that historically, Islam did spread by peaceful means. The Message of the Creator was conveyed to Africa and to southeast Asia by trading Muslims, and today the largest Muslim country in the world is Indonesia. The military expeditions that led to the conquest of large swathes of territory in Europe and central Asia were all marked by tolerance of other creeds and faith.
Again, it is important to remember that Allah declares it IMPOSSIBLE that Islam can be forced on a person, hence Muslims find it useless to try!