Below is part one, we sketched out for the 7 Ecumenical Councils.
If you are not a history or theology nerd, the thought of the Church councils can instantly put you into a coma, yet if you are a Christian you can thank these men for preserving the faith you have received today.
Here is something to remember. These were not men huddled in coffee shops arguing over the finer points of theological minutiae, impacting little their lives or their neighbors. These men were not theorists, they were practitioners of the Faith. They embodied the Way of the Cross passed on to them since the time of Pentecost.
For them, the decisions at the councils were matters of life and death, and to neglect such matters would destroy man's ability to be saved.
The councils were not about theological reflection but about protecting the way of salvation.
God became man so man could become like God, and to dilute this truth endanger's redemption.
Every council is ultimately about this statement, and therefore about Christ. Each council defends His humanity and deity. For if He is not fully God, then He has no power to save man. If He is not fully Man, then man is saved only partially, and not saved at all.
325 - 1st Ecumenical Council at Nicea
Heretics: Arius—Jesus was a created by God and not fully God, but a super-human or demi-God.
Heroes: St. Athanasius.
Decision: Established the Symbol of Faith (Nicene Creed).
Canons: Determined formula for determining Pascha (Easter). Condemned mandatory celibacy for all ranks of clergy. Determined prayers on Sundays should be offered standing.
381 - 2nd Ecumenical Council at Constantinople
Heretics: Macedonianism, Apollinarians, Eunomians, Eudoxians, Sabellians, Marcellians, Photinians.
Heroes: St. Gregory the Theologian (aka St. Gregory of Nazianzus) and St. Gregory of Nyssa
Decision: Condemned Arianism. Condemned Macedonianism which denied divinity of the Holy Spirit. Defined the Holy Trinity as one God in Three Persons: the Father, the Son, and the Holy Spirit each fully God of the same essence. Expanded Symbol of Faith from Nicaea I into what is now commonly labelled the "Nicene Creed" but is more properly known as the Nicene-Constantinopolitan Creed. Condemned Apollinarianism which taught the Lord Jesus Christ possessed the divine Logos in place of a human mind and was therefore fully divine, but not fully human. Condemned Eunomians (an extreme form of Arianism), the Eudoxians (semi-Arians), the Sabellians (who taught the Father, Son, and Holy Spirit were three modes of manifestation of the one God, denying the distinction of Three Persons), the Marcellians (who taught the Logos was an impersonal divine power issued from God entering into a relationship with Jesus to make him the Son of God), and the Photinians (who taught that Jesus was a mere man upon whom the Logos rested).
Canons: Ranked the relative importance of the five patriarchates with Old Rome first and New Rome (Constantinople) second. Established regulations for church discipline, including standing during prayer on Sundays and the days of Pentecost. Established manner in which heretics were to be received into the Church.
431 - 3rd Ecumenical Council at Ephesus
Heroes: St. Cyril of Alexandria
Decision: Condemned Nestorianism which taught a separation between the Lord Jesus Christ's divinity and humanity. Affirmed the term Theotokos. Upheld the Christology of Saint Cyril of Alexandria.
Canons: The Symbol of Faith (Nicene-Constantinopolitan Creed) was affirmed and changes to it were forbidden with punishment of deposition for clerics and excommunication for laity prescribed. Established the rights of each province should be preserved and inviolate (i.e. bishops from one province have no rights over other provinces).