" Colonization of the world, more often than not by robbery and warfare, spread Christianity into the Americas and other corners of the earth, just as Islam was spread throughout Asia and Africa. lt is not a coincidence that the two most widespread religions in the world today are the most warlike and intolerant religions in history. Before the rise of Christianity, religious tolerance, including a large degree of religious freedom, was not only custom but in many ways law under the Roman and Persian empires. They conquered for greed and power, rarely for any declared religious reasons, and actually sought to integrate foreign religions into their civilization, rather than seeking to destroy them. People were generally not killed because they practiced a different religion. Indeed, the Christians were persecuted for denying that the popular gods existed — not for following a different religion. In other words, Christians were persecuted for being intolerant. "

― Richard C. Carrier , Sense and Goodness Without God: A Defense of Metaphysical Naturalism