其實，歷史上的宗教鬥爭，主要是自相殘殺。根據歷史學家的研究，從尼祿到康士坦丁，死於所謂迫害的基督徒加起來不超過兩千。而基督徒殺死不同教派（如路德教），一次就是十萬。十字軍東征時，西歐各信教蠻族大量殺戮拜占庭帝國的教徒（其教義區別是三位一體還是一個上帝），是羅馬帝國最終滅亡的主要原因。
The History Of The Decline And Fall Of The Roman Empire
http://www.ccel.org/g/gibbon/decline/volume1/chap16.htm
“it must still be acknowledged that the Christians, in the course of their intestine dissensions, have inflicted far greater severities on each other than they had experienced from the zeal of infidels.... In the Netherlands alone more than one hundred thousand of the subjects of Charles V. are said to have suffered by the hand of the executioner"
http://www.ccel.org/g/gibbon/decline/volume2/chap58.htm#First
the paths of pilgrimage were obliterated; the chiefs themselves had an imperfect notion of the length of the way and the state of their enemies; and such was the stupidity of the people, that, at the sight of the first city or castle beyond the limits of their knowledge, they were ready to ask whether that was not the Jerusalem...Their rear was again pressed by a herd of two hundred thousand, the most stupid and savage refuse of the people, who mingled with their devotion a brutal license of rapine, prostitution, and drunkenness....
