Hilaire Belloc predicted the future rise of Islam in his book The Great Christian Heresies. This prediction always fascinated me since at least during the last century Islam seemed asleep and quite inconsequential to the West. His prediction was certainly correct. In fact Belloc, writing in the first half of the 20th century summed up the West's thinking on Islam as follows:
"Millions of modern people of the white civilization-that is, the civilization of Europe and America- have forgotten all about Islam. They never come in contact with it. They take for granted that it is decaying, and that, anyway, it is just a foreign religion which will not concern them. It is, as a fact, the most formidable and persistent enemy which our civilization has had, and may at any moment become as large a menace in the future as it has been in the past." (emphasis added)
In his book Belloc classifies Islam as a Christian heresy. It is important to observe the similarities in christianity and Catholicism specifically in order to understand the differences between it and Islam.
Belloc states "It began as a heresy, not as a new religion....It was a perversion of the Christian religion...an adaptation and a misuse of the Christian thing."
Unlike all the other heresiarchs "[T]he chief heresiarch, Mohammed himself, was not, like most heresiarchs, a man of Catholic birth, and doctrine to begin with. He sprang from pagans. But that which he taught was in the main Catholic doctrine, oversimplified. It was the great Catholic world - on the frontiers of which he lived, whose influence was all around him and whose territories he had known by travel-which inspired his convictions."
"Thus the very foundation of his teaching was that prime Catholic doctrine, the unity and omnipotence of God."
"But the central point where his new heresy struck home with a mortal blow against Catholic tradition was a full denial of the Incarnation."
"He taught that our Lord was the greatest of all the prophets, but still only a prophet; a man like other men. He eliminated the Trinity altogether."
"In other words, he, like so many lesser heresiarchs, founded his heresy on simplification...Simplicity was the note of the whole affair; and since all heresies draw their strength from some true doctrine, Mohammedanism drew its strength from the true Catholic doctrines which it retained: the equality of all men before God--"All true believers are brothers."
"The Mohammedan movement was essentailly a "Reformation," and we can discover numerous affinities between Islam and Protestant Reformers- on Images, on the Mass, on Celebacy, etc."