Religious terms beginning with “Ia” through “Inf”
The entries below describe terms found in religious studies, theology, history and non-theistic philosophy. Descriptions are written as neutral orientation rather than as endorsements of any particular claim.
I Ching
A Chinese classic associated with divination and philosophical reflection. Its hexagrams and commentaries have influenced several East Asian intellectual and religious traditions.
Idol and idolatry
An idol may mean an image or representation treated as an object of worship. In some theological writing, the word is also used more broadly for anything given ultimate priority. Idolatry generally refers to worship directed toward a false deity or an image rather than the divine reality recognized by a tradition.
Iftar
The meal with which Muslims traditionally end a daily fast at sunset, especially during Ramadan.
Ignosticism and igtheism
Ignosticism holds that the question of whether God exists cannot be evaluated until the word “God” has a sufficiently clear meaning. Igtheism similarly treats undefined or incoherent claims about a transcendent being as unsuitable for ordinary belief or disbelief.
Ihram
A sacred state and associated clothing observed by Muslims during the hajj and umrah pilgrimages. For many male pilgrims, the clothing consists of two simple, unsewn pieces of fabric.
I.H.S.
A Christian monogram traditionally connected with the first three letters of the Greek form of the name Jesus. Other historical expansions have also been proposed.
Illuminati
The term can describe people regarded as enlightened, the historical Bavarian Illuminati founded in 1776, or modern conspiracy narratives about a secret ruling organization. These meanings should not be treated as interchangeable; claims about a continuing world-controlling group lack reliable historical support.
Iman and imam
Iman commonly refers to faith or belief in Islam. An imam may lead communal prayer and, in some contexts, can denote a significant religious or political leader.
Imitatio Dei
A Latin expression meaning “imitation of God” or “imitation of the gods.” It describes the aspiration to embody divine or godly qualities in conduct.
Immaculate Conception
In Roman Catholic teaching, the belief that Mary was preserved from original sin from the beginning of her own conception. It is distinct from beliefs about the conception of Jesus.
Immanence and imminence
Immanence describes the presence of the divine within or close to the created world. Imminence describes the expectation that an event is near in time, such as an anticipated religious revelation or return.
Immersion
In baptismal practice, immersion means placing the person fully or substantially in water. Christian communities differ on whether baptism requires immersion or may also be performed through pouring or sprinkling.
Immorality
Conduct judged to violate a particular moral framework. Moral evaluations may differ among religions, denominations and secular ethical systems, and may change as communities reconsider inherited practices.
Immortality
The idea that a being or person continues without end. Religious teachings vary widely: some describe divine immortality, eternal life after salvation, continued existence in another realm, or a finite existence followed by final cessation.
Impeccability
The theological claim that a particular person, especially Jesus in some Christian traditions, could not commit sin.
Imprecation and imprecatory prayer
An imprecation is a curse or appeal for harm. An imprecatory prayer asks a deity to judge or punish an opponent. Such passages are interpreted differently across religious communities.
Imputation
The assigning of a quality, status or responsibility to another person. In some Christian doctrines, imputation describes how Adam’s disobedience or human sinfulness is related to later humanity; other traditions reject or reinterpret that account.
Inability, total
An alternative expression associated with the doctrine of total depravity in some Christian theological systems, referring to humanity’s inability to turn toward God without divine assistance.
Incarnation
The embodiment of a spiritual or divine being in physical form. In mainstream Christianity, the term refers to God becoming human in Jesus; other Christian and non-Christian traditions understand the idea differently or reject it.
Inclusivism
A position that treats one’s own religious tradition as uniquely or especially true while allowing that other traditions may contain truth and that their followers may receive divine favor. It is often contrasted with exclusivism and pluralism.
Indulgence
In Catholic theology, a remission of temporal consequences associated with sin after forgiveness. Historical abuses involving the sale of indulgences contributed to criticism during the Protestant Reformation; contemporary teaching does not treat an indulgence as buying forgiveness.
Inerrancy
The belief that a sacred text is free from error, often with reference to its original form. Views differ over whether inerrancy covers every detail or only moral, spiritual and religious teaching. See biblical inerrancy.
Infallibility
When applied to scripture, infallibility generally means that the text is wholly trustworthy for its intended purpose, though interpretations vary. In Roman Catholic teaching, papal infallibility refers to a narrowly defined claim about formal teaching on faith and morals, not to every statement made by a pope.
Infidel
An older term for someone who does not share a speaker’s religion. Because it has often been used dismissively, neutral descriptions such as “non-believer,” “outsider,” or the person’s own religious identity are usually preferable.
Reading note
Glossary entries simplify complex histories. For a fuller treatment, compare the linked essays and consult the wider glossary rather than treating one definition as universal.
Continue the glossary
Terms beginning with INI through IZ appear in the next list.
Related reading
Explore comparative religion, biblical inerrancy, or potentially confusing terms.