"Christians have historically referred to people outside their religious group as infidels, somebody who has actively rejected the Christian religion. It only became a well established notion in English sometime in the early sixteenth century, when Jews or "Mohammedans"(Muslims), were described as active opponents to Christianity, and as such infidel was seen as term of contempt. In Catholic doctrine, an infidel is one who does not believe in the doctrine at all and is thus distinct from a heretic, who is one seen as having fallen astray from true doctrine, i.e. by denying the divinity of Jesus. Similarly, the ecclesiastical term was also used by the Methodist Church, in reference to those "without faith"."
They have certainly disbelieved who say that Allah is Christ, the son of Mary. Say, "Then who could prevent Allah at all if He had intended to destroy Christ, the son of Mary, or his mother or everyone on the earth?" And to Allah belongs the dominion of the heavens and the earth and whatever is between them. He creates what He wills, and Allah is over all things competent.
This post was edited by my2cents at January 3, 2017 8:14 PM MST
"Christians have historically referred to people outside their religious group as infidels, somebody who has actively rejected the Christian religion. It only became a well established notion in English sometime in the early sixteenth century, when Jews or "Mohammedans"(Muslims), were described as active opponents to Christianity, and as such infidel was seen as term of contempt. In Catholic doctrine, an infidel is one who does not believe in the doctrine at all and is thus distinct from a heretic, who is one seen as having fallen astray from true doctrine, i.e. by denying the divinity of Jesus. Similarly, the ecclesiastical term was also used by the Methodist Church, in reference to those "without faith"."
This post was edited by CLURT at January 3, 2017 4:51 PM MST
"Christians have historically referred to people outside their religious group as infidels, somebody who has actively rejected the Christian religion. It only became a well established notion in English sometime in the early sixteenth century, when Jews or "Mohammedans"(Muslims), were described as active opponents to Christianity, and as such infidel was seen as term of contempt. In Catholic doctrine, an infidel is one who does not believe in the doctrine at all and is thus distinct from a heretic, who is one seen as having fallen astray from true doctrine, i.e. by denying the divinity of Jesus. Similarly, the ecclesiastical term was also used by the Methodist Church, in reference to those "without faith"."
I think the term came into vogue during the Crusades to describe mainly the Muslims, but actually anyone who didn't subscribe to papal authority. The Orthodox Christians in the "Holy Lands" were not spared by the Crusaders.
The word came into general use after that and applied to all those of different faiths to ones own, including those with no faith at all. So no matter what religion we are following we are all more than 50% infidel. To atheists all theists are infidel to the fundamental principles of atheism.