Adiaphora: Greek, “indifferent matters” — matters in faith or morals not essential to the faith, concerning which variation is licit. Contrast de fide.
Anathema: Greek “accursed”, and therefore “cut off” (from Church) — judgement and punishment against person on basis of theological position contrary to orthodoxy (and therefore also condemnation of that position).
Apostolic succession: transmission of teaching and authority from apostles, person to person, especially from bishop to bishop by ordination with laying on of hands.
Canon: Greek “rule” or “standard”, used especially of Church’s determination of books regarded as scriptural (”canonical” books); cf. regula fidei (Latin, “rule of — doctrinal standard entrusted to the Church by the apostles.
De fide: doctrines belonging to essence or “deposit” of the faith (Jude 1.3); contrast adiaphora.
Erastianism: doctrine or tendency that subordinates Church to rule and determination of the State (from Thomas Erastus, 16th- century Swiss theologian).
Fathers: see patristic.
Filioque: Latin, “and from the Son” — words added to “Nicene Creed” in West concerning origin of the Holy Spirit from the Father “and the Son” together.
Glossolalia: transliteration of word for “speaking in tongues” in New Testament.
Indefectibility of the Church: belief that the Church preserves the faith and, in the long run, fulfils its mission.
Dulia/Hyperdulia/Latria: patristic distinction between, respectively, honour (due to the saints), highest honour (due to Blessed Virgin Mary), and adoration (due only to God).
Lex orandi, lex credendi: Latin, “the rule (or pattern) of prayer is the rule (or pattern) of belief” — statement about foundational role of liturgy and worship as expression of the faith.
Marcionism: dualist heresy of Marcion of Sinope (c.85–c.160), who distinguished between evil creator God of the Old Testament and good redeeming God of the New Testament, rejecting former.
Marks of the Church: description of characteristics of Church in Nicene Creed — “One, Holy, Catholic and Apostolic”.
Paraclete: name for Holy Spirit, from Greek parákletos, derived from John 14-16, meaning comforter or advocate.
Patristic: period of Church Fathers (Greek, patéron; Latin, patrum) and mothers (and study of their writings), roughly until the seventh ecumenical council (AD 787).
Precepts/counsels: moral injunction binding upon all Christians (precepts, e.g. the Ten Commandments); disciplines or states of life conducive to Christian perfection (counsels), especially poverty, chastity, and obedience, not required of all Christians.
Restorationism: rejection of tradition of the Church beyond traditions reconstructed as belonging to the “apostolic period”; characteristic of groups such as Christadelphians and Jehovah’s Witnesses, but also of some Protestant sects.