Oh come on. European nations used Christianity to justify the conquest and enslavement of millions during the colonial era and before. Christianity was used to justify the perpetuation of slavery in the US for 2 centuries. But the practice of Christianity became more enlightened and less barbarous.
You are right to condemn Islamic radicals and terrorists, but trying to criminalize all muslims because of the excesses of some is like trying to condemn all Catholics because of the anti-semitic progroms that were once practiced by many Catholics.
If terrible acts of barbarism can be carried out in the name of Christ - and they have been - without diminishing the value of Christ's message, then the same is true of other religions. It is the failing of men, not the religion, that is the source of terrorism. Islam is just the conduit used to channel human hatreds and ambitions.
Have you forgotton that simply denying the holy trinity and the authority of the Roman Catholic Church was once punished by death? That "heretics" and accused witches were once burned at the stake throughout Western Europe? That adulterers were once stoned on the authority of the Church? That was where Christianity used to be. Sounds a lot like where Islam is now.