Though European Crusaders may have been sincere, they wandered off from the origins of Christianity when they slashed and burned and forced conversions. Jesus never used violence; neither did he call his disciples to use it. Given this historical fact, it is only natural that the New Testament would never endorse violence to spread the word of the true God. Textual reality matches historical reality in the time of Jesus.
In contrast, Muslims who slashed and burned and forced conversions did not wander off from the origins of Islam, but followed it closely. It is a plain and unpleasant historical fact that in the ten years that Muhammad lived in Medina (622-632), he either sent out or went out on seventy-four raids, expeditions, or full-scale wars, which range from small assassination hit squads to the Tabuk Crusade, described above (see 630). Sometimes the expeditions did not result in violence, but a Muslim army always lurked in the background. Muhammad could exact a terrible vengeance on an individual or tribe that double-crossed him. These ten years did not know long stretches of peace.
It is only natural that the Quran would be filled with references to jihad and qital, the latter word meaning only fighting, killing, warring, and slaughtering. Textual reality matches historical reality in the time of Muhammad. And after.
But this means that the Church had to fight back or be swallowed up by an aggressive religion over the centuries. Thus, the Church did not go out and conquer in a mindless, bloodthirsty, and irrational way—though the Christian Crusades were far from perfect.
Islam was the aggressor in its own Crusades, long before the Europeans responded with their own.
Muslim countries believe in something that is the polar opposite of Christianity. Example:
Muslim works to get to heaven vs Christian grace to get to heaven
Muslim conversion by man vs Christian conversion by spirit
Muslim "moon god" vs Christian "son god"
Muslim "allah's will" vs Christian "free choice"
Mohammed on the other hand - himself was a cruel man who committed numerous atrocities and created a religion based not on love, but cruelty to non-believers. And, that god will attract all that worship at the altar of depravity, cruelty, torture, and death to others.
Leaving aside the religious differences, Islam kills every society it comes in contact with. It instills fatalism, a virtual caste system because of its hereditary religious structure, and induces total paralysis because of its hatred of music, art and creativity.
Christians beleive God sent his only son to die for you.
Allah demands Muslims send their only son to die for him.