It is ironic how when Christians engage in apologia for Islam, they inevitably resort to bringing up Christian atrocities.
It is worthwhile pointing out then, that this dark hour did not go on for days, but for centuries. The rampage and destruction was not limited to a scores of Jews on ancient Jerusalem streets, but the whole southern half of France and the near genocidal destruction of the Albigensian. The Teutonic knights carried on even a more literal genocidal campaign, killing for Christ in their violent conversion of the Slavs of eastern Europe. The crusade continues into the new world and similar conversions of the natives, and into the witching times of the wars of religion, where suspicion and paranoia boiled over to where one could never be sure if one's neighbour was a secret Catholic, or Protestant, or witch, or demon.
And how can this be said not to be according to Christian teaching, when it was popes and preachers and the most prominent of Christians that were the greatest advocates of the crusades and the witch burnings?
If it is now universally not considered by us Christians to be Christian in any way shape or form it is because a different form of Christianity, an alternative teaching, finally won the argument. It was an internal battle, a reform from within, and we reformers carried the day. It did not come about because people outside of the faith pointed out what the true faith was, but because Christians themselves chose another path.
But how crass would it be, as those Jews and Muslims were lying bleeding and raped in the Jerusalem streets, for academics to muse to them how we are all children of the same God after all, under Father Abraham?
So far, in Islam, it is the Islamists carrying the day. When the Sufis, and the liberal intellectuals of Islam come out on top, then maybe it will no longer come off as patronizing platitudes to talk of three faith traditions, One God.