Fundamentalism
Fundamentalism is a tendency among certain groups and individuals that is characterized by the application of a strict literal interpretation to scriptures, dogmas, or ideologies, along with a strong belief in the importance of distinguishing one's ingroup and outgroup, which leads to an emphasis on some conception of "purity", and a desire to return to a previous ideal from which advocates believe members have strayed. The term is usually used in the context of religion to indicate an unwavering attachment to a set of irreducible beliefs (the "fundamentals").