It was customary among the more older works of scholastic theology as well as manuals of dogmatic theology (Catholic/Protestant/Orthodox) in conversations on the doctrine of the most Holy Trinity to claim that the complex Nicene formulation of the Trinity was believed already in the New Testament (and some would say in the Old as well). And while the more extreme heterodox groups have always denied this dogma it really was beginning with the advent of the Protestant Reformation (especially the Anabaptists) that this doctrine was called into question occasionally (albeit for different grounds, i.e., a rejection of post Biblical tradition).
The sons of the Reformers, - the radical Lutheran History of Religion critics, also mounted assaults on this doctrine, but again on different grounds, i.e., so-called "dependence" on the Graeco Roman pagan religions on the part of the authors of the New Testament and the early Fathers. The backlash of all this criticism was the conservative stance, which claimed that the Trinity in all its tricky inseminations was found completely in the pages of Scripture. To go beyond this fundamentalistic reasoning was to dangerously flirt with “higher critical liberalism.”
It was left for Pius XII in his Divino Afflante Spiritu which opened up the flood gates for Catholic scholarship to explore the limits of hermeneutics and the literary criticisms, while remaining within the circle of orthodoxy.1 And while Rahner bemoaned the state of Trinitarian study in his day this complaint no longer has any merit.2 Catholic scholars such as Fortman and Brown3 were contending that the New Testament writers had no conception of the Trinity as it was couched in Nicene phraseology but instead they held to an “elemental” Trinitarianism, or the building blocks which later Catholic theologians would use to construct the Trinitarian edifice (guided by the Hand of the Spirit). This is no less than a beautiful example of the "Development of Doctrine" conception as it was classically explained by John Henry Newman.
The earliest post-NT writings seem to support this conclusion.4 In First Clement the Father is intelligibly God and the pre-existence of Christ can be deduced from texts such as (22, 1). The closest thing to a Trinitarian frontal statement is in (58, 2), “As God lives, and the Lord Jesus Christ lives, and the Holy Spirit.”5 The stress throughout Clement is usually on Christ and the Three are rarely mentioned together. In this matter Clement seems very primitive and similar to the statements of Paul in the NT.
In the Ignatian corpus the Development of Doctrine is already beginning to flower. Christ is directly called God fourteen times,6 but as in Clement there is no frontal formulations of the Trinity in Ignatius. As in Clement, Ignatius speaks of the Trinity in its functions rather than in tractarian terms, “Like the stones of a temple, cut for a building of God the Father, you have been lifted up to the top by the crane of Jesus Christ, which is the cross, and the rope of the Holy Spirit (Eph. 9.1). The same things can be said of Hermas, the Didache, the Martyrdom of Polycarp, Barnabas, 2 Clement. All of which speak in Trinitarian language, albeit in a very primitive and rudimentary way.7
It is not an affront to orthodoxy at all to state that the dogma of the Trinity as it was codified in Councils such as that of Nicaea was a careful and divinely guided example of the Development of Doctrine. This view holds that the seeds of Trinitarianism are found already in the Scriptures (both Old and New) but it was left for God’s community over the passing of the centuries to slowly unfold this greatest and central mystery of our faith.
¹ Catholic scholars such as Chenu, Congar, Jungmann, Rahner, de Lubac, Lagrange, Danielou, Bouyer, etc were pioneers in this expedition.
² Studies and monographs on the Trinity are an enormous cache now in the beginning of the twenty-first century. In my opinion the best Catholic exposition of the twentieth century was that of Edmund J. Fortman, The Triune God: A Historical Study of the Doctrine of the Trinity (Oregon: Wipf and Stock, 1999). One of the best Orthodox expositions was Sergius Bulgakov, The Comforter(Eerdmans, 2004). The Protestant expositions on the Trinity was a jumbled mess, that is well chronicled by the Anglican scholar Kevin Giles, Jesus and the Father: Modern Evangelicals Reinvent the Doctrine of the Trinity (Zondervan, 2006) and also Millard J. Erickson, Who’s Tampering with the Trinity?: An Assessment of the Subordination Debate (Kregel Academic, 2009).
³ Fortman, opt cit; R. E. Brown, Biblical Exegesis and Church Doctrine (Paulist, 1985) are just two examples.
⁴ Let me be clear lest I’m misunderstood. I agree with the overwhelming majority of Patristic scholars that Trinitarian language is clearly found in the early pre-Nicene Fathers (as well as the New and Old Testaments). But what I’m saying is that the later fully developed Nicene formulation of the Trinity was an acceptable development of these rudimentary blocks. It should however not be anachronistically be read back into say Paul or Clement when it is simply not there.
⁵ The Three are again mentioned in 42, 3; 46, 6.
⁶ (Eph. 1.1; 7.2; 15.3; 17.2; 18.2; 19.3; Trall. 7.1; Rom. 3.3; 6.3; Smyrn. 1.1; Poly. 8.3).
⁷ In the later so-called “Apologists” such as Justin Martyr et al, we see a clear unfolding of the development of Trinitarian insight.