We've seen that the Qur'an endorses jihad, or "struggle," and that can be physical as well as psychosocial. Islam also endorses hijra, or migration to a new geographical area in which Islam does not dominate, for the purpose of dominating the people who are there, absorbing their wealth, and winning the culture for Islam. Both of these actions on earth are thought to bear big rewards in the afterlife.
These are similar to, but on the other hand quite different from, two Christian imperatives in the Bible to spread the Gospel, but never using violence or force, and to go on missions to foreign people who don't know about Jesus, but only for spiritual purposes, never for political or economic gain.
Now comes a third key concept from the Qur'an which does not square at all with Christian ideas. In Islam, it is OK to practice taqiyya (tuh KEY uh) — purposeful deception and lying — as long as it aids Allah and the advancement of Islam in the long run, saves the person from death or harm, or preserves the person's property. Taqiyya authorizes Muslims to appear to be something or someone that they are not, to conceal their true identity or intentions, and to lie in order to keep from getting killed or hurt. It is a crucial tool being used by jihadi terrorists in the world today, one that they feel can be justified in the Qur'an.
In stark contrast is the Judeo-Christian principle that lying and deception are always wrong. The Ninth Commandment, "Thou shalt not bear false witness against thy neighbour" (Exodus 20:16), makes that clear.
In Islamic history, though, taqiyya has acted as a sort of camouflage or cloak for Muslims interacting with non-Muslims, especially those who pose a threat. The word means "to safeguard." It's a defense mechanism first described in the Qur'an when Ammar, son of Yasser, pretended not to believe in Muhammad so that the pagan tribesmen who had captured him would not kill him, as they had killed his parents. As long as he held fast to Allah in his heart, and just outwardly pretended not to, he could get away with what otherwise would be an unethical lie.
It's not just used in battle situations. We find that Shiite Muslims passing through Sunni Muslim areas use taqiyya to "blend in" and avoid attack or persecution. Devout Muslims even drink wine with non-Muslims, normally a huge no-no, if in doing so they can maintain their "cover" and save their lives. Taqiyya is often used by terrorists in the form of medical fraud, using ambulances with hidden bombs that later blow up and cause much more destruction, and telling "phony atrocity" stories with fake bandages to the media to gain sympathy for Islamic causes in a dishonest way. In the U.S., there has been a growing number of fraudulent claims of hate crimes that, one by one, are being exposed. But the chances are good that many, if not most, succeed in deceiving the American people in one way or another, for Islam's gain. And again, it must be pointed out, to the Muslim mind, acts of taqiyya are good, not bad.
In Islam, "the little white lie" is acceptable for good purposes such as putting a marriage back together, or making peace between neighbors. Lies may be used on the offense, even when you are not at risk, if it is for Allah's sake. The key is if telling the truth would not secure the benefit; in that case, a lie is acceptable. Muhammad himself used deception to make foes surrender. One of the most famous examples is the Treaty of Hudaibiya (hoo duh BYE yuh), in which Muhammad first signed a truce agreement with the local tribe, but two years later, after his forces had grown stronger, he decreed that it was time to break the truce, and he killed or enslaved many of his opponents. To put it bluntly, the Prophet of Islam justified a lie in order to kill an enemy. This poses one of the starkest differences between Muhammad and Jesus Christ.
And the thing that Christians have to remember is that Muslims have no shame about this practice. It is acceptable, under the Qur'an.