Apollinarianism: The view, named after the 4th century Alexandrian
theologian Apollinarius, that in the Incarnation the divine Word replaced
the rational human soul, so that Jesus was the Word united with a human
body, not with a whole human being. Apollinarianism is rejected as a
heresy because it implies that Jesus, not having a human soul, is not
fully human.
apophatic: From the Greek word for “denial” or “negation,” apophatic
theology is the characteristically Eastern Orthodox approach of refusing
to describe God directly but only to say what God is not. When such an
approach is used in the West it is called the via negativa (Latin for “way
of negation”).
Apostle’s Creed: This Western baptismal creed is the earliest creed known
to us.
apostolic succession: The historical continuity of bishops being consecrated
by bishops, who were themselves consecrated by bishops, etc., going back
to the original twelve apostles of Christ. For Eastern Orthodox, Roman
Catholics, and Anglicans, apostolic succession is a necessary feature of the
episcopate, which means that no one who is consecrated outside the apostolic
succession is really a bishop.
archon: The Greek word for “ruler” or “prince,” used by the Gnostics as a
term for the enemy spirits of the visible heavens who block the soul’s escape
from this world. The chief of the archons is the God of the Jews, who in his
ignorance created the evil, physical world and in his arrogance thinks he is
the only God.
Arianism: The theology attributed to 4th-century Alexandrian presbyter
Arius, a radical form of subordinationism in which the preexistent word of
God (prior to the Incarnation) is regarded as a creation of God the Father,
so that “there was once when he was not.” The Council of Nicaea 325
condemned this view.