Mystery, or Sacrament
Archimandrite Nikifor’s Biblical Encyclopedia
(Eph. 5:31–32)—in ecclesiastical usage, a sacred action through which God invisibly communicates saving grace by a visible sign. The Eastern Church traditionally numbers seven principal sacraments: Baptism, Chrismation, the Eucharist, Repentance, Holy Orders, Marriage, and Anointing of the Sick. The biblical Greek mystērion more broadly denotes a divine mystery once hidden and now revealed; in Ephesians 5 it refers above all to the union of Christ and the Church, which gives Christian marriage its sacramental depth. See the separate entries for the individual sacraments.