@Johann
A.D. 300 Trinitarian prayers unknown in the Church.
A.D. 325 "Nicene Creed" affirms Christ to be "Very God of Very God".
A.D. 370 Doxology composed: "Glory to the Father, and to the Son, and to the Holy Spirit: as it was in the beginning, is now, and will be for ever. Amen."
A.D. 381 Council of Constantinople invents "Three persons in One God".
A.D. 388 Emperor Theodosius threatens punishment to all who won't worship the Trinity.
A.D. 519 Doxology ordered to be sung in all the Churches.
A.D. 669 Clergy commanded to commit to memory the "Athanasian Creed" (see below).
A.D. 826 Bishop Basil, required the clergy to repeat the " Athanasian Creed" every Sunday.
Ignatius of Antioch (c. 35–108 AD)
“For our God, Jesus Christ, was conceived by Mary according to God’s dispensation, of the seed of David, but also of the Holy Spirit.” (Letter to the Ephesians, Chapter 18)
Ignatius affirms Jesus Christ as God and mentions the Holy Spirit in unity with God’s dispensation, hinting at a Trinitarian understanding.
2. Justin Martyr (c. 100–165 AD)
“For, in the name of God, the Father and Lord of the universe, and of our Savior Jesus Christ, and of the Holy Spirit, they then receive the washing with water.” (First Apology, Chapter 61)
Justin refers to baptism being administered in the name of the Father, Son, and Holy Spirit, reflecting the Trinitarian formula from Matthew 28:19.
3. Theophilus of Antioch (c. 120–190 AD)
“The three days which were before the luminaries are types of the Trinity, of God, and His Word, and His wisdom.” (To Autolycus, Book 2, Chapter 15)
Theophilus uses the term "Trinity" (trias in Greek), explicitly identifying God, His Word (Logos), and His Wisdom (often understood as the Spirit).
4. Irenaeus of Lyons (c. 130–202 AD)
“For with Him were always present the Word and Wisdom, the Son and the Spirit, by whom and in whom, freely and spontaneously, He made all things.” (Against Heresies, Book 4, Chapter 20, Section 1)
Irenaeus clearly speaks of the Son and Spirit as eternally existing with the Father, participating in creation.
5. Tertullian (c. 155–220 AD)
“We define that there are two, the Father and the Son, and three with the Holy Spirit, and this number is made by the pattern of salvation...which brings about unity in trinity, interrelating the three: the Father, the Son, and the Holy Spirit.” (Against Praxeas, Chapter 2)
Tertullian gives a detailed explanation of the Trinity, using the term Trinitas in Latin, emphasizing the unity and distinct persons.
6. Clement of Alexandria (c. 150–215 AD)
“O mystic marvel! The universal Father is one, and one the universal Word, and the Holy Spirit is one and the same everywhere.” (Stromata, Book 5, Chapter 14)
Clement describes the Father, Son (Word), and Holy Spirit as one in essence and universal presence.
7. Origen (c. 185–254 AD)
“We worship one God, the Father and the Son and the Holy Spirit. These, by the way, are the three most essential truths concerning the omnipotent God.” (On First Principles, Book 1, Chapter 3)
Origen defends the worship of the triune God and presents the three persons as fundamental truths.
8. Hippolytus of Rome (c. 170–235 AD)
“The Logos alone of this God is from God himself; wherefore also the Logos is God, being the substance of God.” (Refutation of All Heresies, Book 10, Chapter 33)
Hippolytus emphasizes the divinity of the Logos (Jesus) in relation to God and mentions the Spirit's participation in the Godhead.
9. Novatian (c. 200–258 AD)
“What then is the Holy Spirit? An essential part of the Godhead, deriving from the Father and the Son.” (On the Trinity, Chapter 16)
Novatian speaks of the Holy Spirit as part of the Godhead, derived from the Father and the Son.
10. Cyprian of Carthage (c. 200–258 AD)
“The Lord said, ‘Go therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit.’” (Epistle 73)
Cyprian echoes the Trinitarian baptismal formula from Matthew 28:19.
Shalom
J.