Unbelievers. Only others can be the ones not believing what you believe at the given moment (you can of course believe the opposite later, but you just "changed your mind" or something). Religions use that word to proclaim or even demand that something bad should happen to the others.

Interestingly, some people discussing the leak show emotional and "religiously righteous" response to the people who possibly made or even just considered an act of "infidelity" (not to be confused with the "infidels.")

Infidel: "Late 15th century: from French infidèle or Latin infidelis, from in- 'not' + fidelis 'faithful' (from fides 'faith', related to fidere 'to trust'). The word originally denoted a person of a religion other than one's own, specifically a Muslim (to a Christian), a Christian (to a Muslim), or a Gentile (to a Jew)."

C.f. Barbarian, 2: "2. Hist. a. One not a Greek. b. One living outside the pale of the Roman empire and its civilization, applied especially to the northern nations that overthrew them. c. One outside the pale of Christian civilization. d. With the Italians of the Renascence: One of a nation outside of Italy."