That is true. Rome's fall was actually in part caused by Christianity.
If we were to put the Christian persecution of the Pagans following Constantine into a present day context we might do so as follows. It will start with crowds harassing ministers and priests in the streets. It proceeds to riots and the burning of churches with the consequent killing of pastors and prominent members of congregations. This proceeds to attacking bible colleges and seminaries. The faculty are murdered, the libraries are burned and the buildings demolished. In the meantime church after church is attacked and burned. The diehard Christians are shipped off to concentration camps for interrogation (torture) and execution. Now, imagine that not only Christian institutions are treated in this way but every institution that has Christians in the faculty. Everything tainted in the least bit with Christianity is attacked and destroyed and any objectors are tortured and killed. One after another our schools and academies and universities are destroyed, their teachers tortured and killed. Libraries great and small are put to the torch. Die hard Christians are hunted down to the few remaining churches and die en masse as martyrs to their faith. Now imagine this happening over three centuries. In the end the world devolves into a very long dark age of ignorance and superstition. Replace the word Christian with the word Pagan and you might begin to imagine the persecution and the suffering and why the Roman Empire collapsed into barbarism for the next thousand years.
