The inward life of the Christian Church is mystical (or sacramental). The word “mysteries” (Greek mysteria) is the term used in the Orthodox East; “sacraments” (Latin sacramenta), the term used in the Latin West. So, how and when did Western Latin and Eastern Orthodox come to identify and accept the seven sacraments, or mysteries of the Christian Church?
One might reasonably assume that the seven Sacraments (Mysteries) were determined early in the period of the united Church (AD 33 – 1054). That assumption would be false.
One of the renowned teachers of the united Church, Pseudo-Dionysius the Areopagite (6th Century) listed six sacraments in his work The Ecclesiastical Hierarchy (ca. AD 500): baptism, Eucharist, confirmation, priesthood, the consecration of monks, and rites for the dead.
Two centuries later, another early teacher revered East and West, John of Damascus (675-749), mentions only two sacraments: Baptism together with the corresponding chrismation and the Eucharist (Communion), the only two mysteries identified in the New Testament and instituted by Jesus.
Clearly, there was no unanimity on the identity or number of sacraments/mysteries in the first 1,000 years of the unified Christian Church, nor at the time of the Great East-West Schism of 1054.
In the post-Schism Latin West, Peter Lombard (1100-1164), in his fourth Book of Sentences (d.ii, n.1), enumerated the seven sacraments. This list of sacraments was accepted by the Western Latin Roman Church at the Fourth Lateran Council in 1215.
49 years later, during the Second Ecumenical Council of Lyons in 1274, Eastern Greek theologians, under Byzantine Emperor Michael VIII Palaiologos (in his Profession of Faith), accepted the seven Latin Sacraments: Baptism, Confirmation (Chrismation), Eucharist, Penance, Priesthood, Marriage, and Anointing of the Sick.
So, clearly, neither the Seven Holy Sacraments of the Roman Catholic Church nor the Seven Holy Mysteries of the Eastern Orthodox Church are First Thoughts of God, but mostly, save two, distant Afterthoughts of Man, codified a thousand years after Jesus and the Apostolic age.
First Thoughts 