How about them? No one has said that no one can commit terrorism in the name of Christianity. But anyone who does, does not have the mandate, expressed again and again, of Christianity's holy book.
historically wrong
Killing unbelievers was actually declared by popes Leo IV and John VIII to be spiritually beneficial for Christian soldiers: Their sins could be erased if they killed in defense of the Church.
the bible itself does expressly not only allows for such violence, it is often recited with praise.... as it was commanded by god himself on several occasions
God demands purity and strict obedience, and idolatry and blasphemy were punishable by death (Exodus 20:3, 5)
God can justify the slaughter of entire communities (Deuteronomy 20:10-18).
"[Joshua's army killed everyone in Jericho], both men and women, young and old, oxen, sheep, and donkeys.... Joshua defeated the whole land... he left no one remaining, but utterly destroyed all that breathed, as the LORD God of Israel commanded."
(Joshua 6:21 and 10:40)
"I will sing praise to your name, O Most High.... The enemies have vanished in everlasting ruins; their cities you have rooted out; the very memory of them has perished.... The LORD will swallow [up his enemies] in his wrath, and fire will consume them. [He] will destroy their offspring from the earth ... their children from ... humankind." (Psalms 9:2, 6, and 21:9-10)
"[Thousands of angels] proclaimed with loud voices: 'Worthy is the Lamb who was slain, to receive power and wealth, wisdom and might, honor and glory and praise!'... I saw heaven wide open, and a white horse appeared; its rider's name was Faithful and True, for he is just in judgment and just in war.... [H]e was robed in a garment dyed in blood, and he was called the Word of God. The armies of heaven followed him.... Out of his mouth came a sharp sword to smite the nations; for it is he who will rule them with a rod of iron, and tread the winepress of the fierce wrath of God the sovereign Lord." (Revelation 5:11-12 and 19:11, 13-15)