What's the difference between an Islamic Terrorist and a Christian Martyr?

In the light of the recent murder of Jacques Harmel, we've been considering Jesus' teaching on loving enemies and pray for those who persecute you. 

Today, I want to address the question of the difference between an Islamic Terrorist martyr and a Christian martyr. I'm reminded of some words from a great book called "Let the Nations be Glad":

"There is a fundamental difference between Christian martyrs and those who have gained notoriety through terrorism. First the life of a Christian martyr is taken by those he wants to save. He does not fall on his own sword and he does not use it against his adversary. Second, Christian martyrs do not pursue death; they pursue love. Christians do not advance the cause of the gospel by the use of the sword: "For all who take the sword will perish by the sword (Matthew 26:52). Christianity advance not by shedding the blood of others, even if its mingled with ours. It advances by  suffering to bring life, not suffering to cause death."