The following is a list of religious slurs that are, or have been, used as insinuations or allegations about adherents of a given religion or to refer to them in a derogatory (critical or disrespectful), pejorative (disapproving or contemptuous), or insulting manner.
Portuguese for a Muslim person, especially in Brazil. It may vary from kindly jocose to highly offensive depending on individual perceptions of Islam and Muslims. Also mouro (Moor) and turco (Turk) (terms that were synonymous for such usage in most European languages in the past), that may also denote (pejoratively or not) people of North African, Middle Eastern or South Asian background irrespectively of religion. It was popularized by a humorous 1941 Rio de Janeiro Carnaval's MPBmarchinha that makes reference to Islam and the desert, a stereotypical Middle Eastern scenery.
literally "Atheist, thanks to God", Portuguese for an atheist who is seen as actually a closeted non-atheist (employed mainly among those critics of militant atheism or atheism in general). Used to denote a biased sentiment that his or her religious beliefs are based on just a pseudo-intellectual and/or teenage fad, and to shun militant atheism and secularism supposedly denouncing their rants on religion or Christianity as a denial of their own untrue lack of belief.
(UK, Australia & New Zealand) a Protestant, particularly one from a Pentecostal or fundamentalist denomination, who believes in the fundamentalist authority of the Bible; also commonly used universally against Christians who are perceived to go out of their way to force their faith upon others.
(U.S.) someone perceived as aggressively imposing their Christian beliefs upon others. The term derives from preachers thumping their hands down on the Bible, or thumping the Bible itself, to emphasize a point during a sermon. The term's target domain is broad and can often extend to anyone engaged in a public show of religion, fundamentalist or not. The term is most commonly used in English-speaking countries.
Portuguese for an especially devout, committed, proselitist or conservative Christian, most especially Catholics, but also Orthodox and traditional Protestants (faiths that are not supposed by Brazilians to be necessarily full of self-giving or to be of cult-like characteristics). It is used too, more pejoratively, when a Christian tries to pass as very committed to religious mores, and even makes commentary of others' misbehavior or lack of commitment to faith, but secretly takes on behaviors that are not regarded as adequate by his or her religious community, also referred to as falsa beata, literally "fake goody".
Pejorative Spanish word referring to Catholics who spend much time in church or taking about religion. It's the result of joining the words "chupa" and "cirio", meaning "suck" and "altar candle", or "altar candle sucker".
Literally "believer" or "faithful one" (according to popular belief, it either started as self-designation – as many have a proud on self-referring to as such – or as a militant atheist denounce against belief in spite of the lack of or against current evidence, as shown in a famous Carl Sagan's phrase), mainly used in Portuguese for a Mormon, a Scientologist, a Jehovah's Witness or a Protestant Christian (especially those of Charismatic, Evangelical, Pentecostal or fundamentalist belief), as well as members of minor cults. Apart of being used as a slur against those perceived to have become members of cults, it is used in a general way to shun non-Muslims who are seen as aggressively proselitist and/or fundamentalist, or those non-Catholics that base their militant conservative political and ideological beliefs and/or prejudices against those of different religions, sexual orientations and harmless lifestyles on religious mores. Further, there is also the term crentino, fusion of crente and cretino (cretin), that refers to the priests that have a considerable material profit with their so-called crente following.
(US) a ritualistic Protestant prone to rolling on the floor, suffering from fits or "speaking in tongues" (Pentecostals during worship or prayer). The term holy roller, however, is applied to some Evangelical Protestants, especially charismatics, if they are vocal about their own religious views or critical of individuals who do not meet their moral standards. Similar to Bible thumper. 
A common biased use for this term (that has other uses, as macumba carries more than a single meaning) is Portuguese for those of Spiritist and/or Afro-Brazilian practices, including those that only practice the vast majority that are not related to the doing of harm to others through rituals. It can be roughly translated as "fetishist that practices sorcery". Practicers of quimbanda, though, that does not prohibit the use of rituals for obtaining harm of others (despacho), may be referred to as macumbeiros in a less polemic and questionable way, as those of other Afro-Brazilian beliefs see the evil-doing associated with it as misleading of their shared mission (though they will most likely still see this slur as highly offensive). Some people of Abrahamic belief may expand the term to all those of non-Abrahamic belief or practice, such as Hinduists, neopagans and freemasons, because Afro-Brazilian spirits are associated with the devil by many Pentecostals and Evangelicals, so other creeds and religious rituals incomprehensible to their worldview are likely to be seen to partake from the same origin.
(Iberian Peninsula and Latin America) a Jewish convert to Christianity, usually for social and not spiritual reasons; derives from the Inquisition; today, can refer to a Jew who marries a Catholic. Marrano is also a Spanish slang term for "dirty pig" or "swine", while Portuguese marrão refers to a non-castrated swine or an ungenerous person (probably with influence of the common anti-Semite stereotype). Because of its questionable undertones, publications and education in Portuguese-speaking countries now refer to those Jewish converts with the much more neutral term cristão-novo (new Christian), in contrast to the cristãos-velhos, Iberians without any sort of [traceable] non-European descent.
(Ireland/UK) a pro-British Ulster Protestant, referring to supporters of the Orange Order.
(AUS Catholics (particularly school kids)) a Protestant, particularly a rival kid from a Protestant school. "Proddywhoddy" and "proddywoddy" are used in children's school rhymes in Cork.
A member of the Religious Society of Friends. Originally derogatory, later embraced by Friends. According to George Fox, founder of the Society of Friends, British Magistrate Gervase Bennet "was the first person that called us Quakers, because I bade them tremble at the word of the Lord." Fox had been brought before Bennet on a charge of Blasphemy.