For those who would like go go deeper in their Study on Sundays Topic.
3-23-2025 The Divine Connection
Historical Development of the Doctrine of the Trinity
The historical development of the doctrine of the Trinity is a process which was characterized at first by foreshadowing and revelation and then later by clarification and expression. It is the story of the church, being led by the Spirit in all truth (John 16:13), clarifying their monotheism in light of the reality of the Son’s incarnation and the subsequent outpouring and indwelling of the Holy Spirit. It is not the story of elaboration and invention, but rather of illumination and fidelity to Scripture.
The doctrine of the Trinity first emerges in Scripture as a mystery foreshadowed in the Old Testament and disclosed in the New Testament. After the incarnation the church was left to grapple with the confession of monotheism on one hand and, on the other, the reality of the God-man, Jesus Christ, and the tangible presence of the Holy Spirit. Being guided by the Holy Spirit “into all truth” (John 16:13), the newborn church expressed belief in the Trinity through the New Testament’s soteriological narrative (Matt 3:13–17), liturgical triadic formulas (Matt 28:16–20; 2 Cor 13:14; Eph 4:4–6), and explicit attribution of divinity to the Son (John 1:1, 18) and Spirit (Acts 5:3–4; 1 Cor 3:16; 6:19). The testimony of Scripture provided the church with a reliable witness to the reality of the Trinity as it moved into the coming centuries.
By the time of the apostolic fathers in the late first century and early second century, the doctrine of the Trinity had taken hold in the church and its language. We find testimony to the Trinity early on in Ignatius of Antioch (Letter to the Magnesians 13) and Polycarp (Martyrdom of Polycarp 14). In the mid- to late second century, we find that apologists such as Justin (First Apology 61) and Irenaeus (Against Heresies 4.20) continued to affirm the church’s Trinitarian confession. Although at this time some attempts at expressing the doctrine of the Trinity appear clumsy in hindsight, those attempts should not be confused with genuine heresies, such as modalism, which were consistently recognized as deviations from the church’s confession. Instead, even the poorest attempts by early Christian authors reflect both the universal belief in the Trinity and the need for universal language to clarify that belief. It should be noted that it is here, in the second century, that we find in Theophilus (Letter to Autolycus 2:15) the first use of the term “Trinity,” which was subsequently utilized by fathers of the third century such as Tertullian (Against Praxeas 23) and Gregory Thaumaturgus (Declaration of Faith). Ultimately, however, this term would not suffice to provide universal language that adequately clarifies the church’s belief.
In the Trinitarian controversies that dominated the fourth century, we find the church desperately trying to elucidate the doctrine of the Trinity in a manner completely faithful to the witness of Scripture. In the First Council of Nicaea (325), the church found the answer in the Greek word homoousios, a technical term meaning “same substance.” This word was used to reflect the church’s belief in the full divinity of the incarnate Son of God over against Arian denials, confessing that Jesus was indeed “Light of Light, true God of true God, begotten and not made, being of one substance (homoousios) with the Father.” In 381 the First Council of Constantinople further clarified the dogma of the Trinity by explicitly confessing the divine Holy Spirit as “the Lord and Giver of life, who proceeds from the Father, and who with the Father and the Son together is worshiped and glorified, and who spoke by the prophets.” The five ecumenical councils that followed (Ephesus in 431, Chalcedon in 451, Constantinople II in 553, Constantinople III in 680–681, and Nicaea II in 787) provided further clarification on christological matters.
As the church moved forward into fifth century and beyond, it looked back on the councils of Nicaea and Constantinople as representative of that universal faith believed by all true Christians everywhere, and the creed that emerged from those councils (the Niceno-Constantinopolitan Creed) is still considered indicative of essential Christian dogma. While the centuries have witnessed further elaborations on the Trinity (such as Augustine’s On the Trinity as well as the controversy over the filioque), the confession has remained the same. Even in the attempt during and after the Enlightenment to make the doctrine of the Trinity theologically and philosophically unfashionable, the church has consistently held fast to that ancient dogma proclaimed in Scripture and faithfully expressed in the creed. There is one God who eternally exists in three persons: Father, Son, and Holy Spirit.
Passages
KEY VERSES
Mt 3:13–17; Mt 28:16–20; 2 Co 13:14; Eph 4:4–6; Jn 1:1; Jn 1:18; Ac 5:3–4; 1 Co 3:16; 1 Co 6:19
Lycans, Z. (2018). Historical Development of the Doctrine of the Trinity. In M. Ward, J. Parks, B. Ellis, & T. Hains (Eds.), Lexham Survey of Theology. Lexham Press.