First Council of Constantinople I

Old Testament: The First Book of the Kings 1-2
New Testament: The Holy Gospel According to St. John 15-18
Book of Concord: SD Art. 11 paragraphs 50-75
Small Catechism: The Holy Eucharist
Psalms: Morning - 73, 74
Evening - 75-77

The Orthodox Church in America seems to commemorate the holy fathers of the First Council of Constantinople today (as well as the martyr Bishop Basiliscus of Comana, St. John-Vladimir the Wonderworker, and others, including the icon of the Mother of God of Cyprus). The holy and ecumenical council included 150 bishops, all from the east.

The council's primary purpose was to defend the consubstantiality of the Holy Spirit with the Father. Thus, the one homousion of God contained three hypostases. The longer third article of the Nicene Creed was added (thus the occassional name "Niceno-Constantinopolitan Creed"), as well as the condemnation of Arianism (again) and Apollonarianism.

This council has some noteriety in that it declared seven canons of which three are slightly questioned. The biggest issue was the declaration of the Bishop of Constantinople having the pre-eminence of honour after the Bishop of Rome. Because of the nature of this council having only eastern bishops, it was slightly questioned as an ecumenical council until it was affirmed at the Council of Chalcedon.

"I believe in the Holy Spirit, the Lord and giver of life, who proceeds from the Father [and the Son], who with the Father and the Son together is worshiped and glorified, who spoke by the prophets. And I believe in one holy Catholic and apostolic Church, I acknowledge one Baptism for the remission of sins, and I look for the resurrection of the dead and the life + of the world to come. Amen." - 3rd Article, Nicene Creed.

"Oh Heavenly King, O Comforter, Spirit of Truth who art in all places and fillest all things. Treasury of Blessings and Giver of Life. Come and abide in us, and save our souls Gracious Lord."

"Holy Spirit, light divine,
Shine upon this heart of mine;
Chase the shades of night away,
Turn the darkness into day." - Holy Spirit, Light Divine v.1 LSB 496