Before the Nicene Creed
Since Christianity is a religion derived from Judaism, it should not be a surprise that from the beginning it has been adamantly monotheistic. The early 2nd century Apologists like Justin Martyr rejected Marcionite and Gnostic dualism wholeheartedly and asserted the oneness of God in strong, almost Platonistic language.
The difficulty present in early Christianity was integrating this strongly monotheistic tradition with the new revelation available in Jesus Christ. Essentially, this new revelation was that God had made Himself known through and in the person of Jesus of Nazareth, the hoped-for Messiah of Israel. This God-Man was clearly described as being divine, yet was presented as a distinct person from God the Father. Christ himself revealed the coming Spirit of God who also possessed divine attributes and too was spoken of as distinct from the Father. These statements of Jesus, along with the teaching of the epistles of Paul and John, presented a unique theological challenge to the early Christians.
By the close of the New Testament era, there were clear statements of Christ's pre-existence and His role in the creation of the world (cf. John 1). From the words of the NT Scriptures alone there were nascent suggestions of Trinitarianism in various liturgical formulations of the early church; for instance, baptisms in the Church were always done in the name of the Father, the Son and the Holy Spirit.
Speaking of Trinitarianism in the ante-Nicene period is somewhat anachronistic, since the word Trinity (Lat. trinitas) was first coined by the Latin father Tertullian in the 2nd century, and the Trinitarian doctrine was not solidified as dogma until the early 4th century. A systematic presentation of the development of Trinitarian theology is best seen in a roughly chronological fashion, from the the Canon of Scripture, through the early church fathers, and the world-defying Athanasius. However, Roger Olson reminds us that "Christian belief in God as triune did not arise in the fourth century with Roman emporer Constantine and the Christian bishops that he dominated. Belief that it arose then as part of a vague paganizing or Hellenizing of Christianity is a caricature often promoted by anti-trinitarian cults and sects" (Roger Olson, The Mosaic of Christian Belief, p. 135)
The apostolic fathers
The Apostolic Fathers should be seen more as bearers of the faith than as theologians wrestling with issues of hypostasis and homoousios. There is no explicit formulation of Trinitarian theology extant in their writings; what is immediately apparent, however, is the use of what patristic scholars call "dyadic" and "triadic" formulae. In addition to this, we have various apostolic Fathers confessing that Jesus Christ is not the Son of God in merely human terms, but in divine terms as well.
A good example of the so-called triadic formulae occurs in the Church father Ignatius (30-107 AD), who exhorts the Magnesians to "study, therefore, to be established in the doctrines of the Lord and the apostles, that so all things, whatsoever ye do, may prosper both in the flesh and spirit; in faith and love; in the Son, and in the Father, and in the Spirit; in the beginning and in the end; with your most admirable bishop, and the well-compacted spiritual crown of your presbytery, and the deacons who are according to God. Be ye subject to the bishop, and to one another, as Jesus Christ to the Father, according to the flesh, and the apostles to Christ, and to the Father, and to the Spirit; that so there may be a union both fleshly and spiritual" (Epistle to the Magnesians, 13:1, 2 emphasis added).
Ignatius also goes on his letter to the Ephesians to explicitly confess that "our God, Jesus Christ, was, according to the appointment of God, conceived in the womb by Mary, of the seed of David, but by the Holy Ghost. He was born and baptized, that by His passion He might purify the water." (Epistle to the Ephesians, 18:2)
In this passage of Ignatius one will note two things: first, that this church Father wholeheartedly affirms the deity of Jesus of Nazereth while at the same time alluding to a sort of economy between God and Jesus Christ, which is essentially what the later doctrine of the Trinity sought to express in the most explicit terms.
The use of trinitarian terms has received considerable attack throughout the years of church history. Such terms are: homoousios, person, essence, and nature among others. While it is true that these terms were borrowed from Greek philosophy, critics generally go a step further and assert one of three (or even all) points: (1) Greek philosophy, with its terms, infiltrated Christian theology and therefore corrupted the orthodox doctrine of God, (2) the use of non-biblical terms violates sola scriptura, or (3) the use of non-biblical terms results in non-biblical (i.e. false) theology. Therefore, it becomes important to understand these trinitarian terms, where they came from, how they are defined, and if we are justified in using them.
The use of non-biblical language
Christians should be cautious while using language not found in Scripture to define God, however, they should not refrain from doing so. John Frame, in his Doctrine of God (2002), shows that "as it struggled to define the doctrine of the Trinity precisely, the church came to adopt specialized terminology for God's oneness and threeness... in general, these terms have served the church well. But they have also raised additional questions and caused some misunderstandings," (p. 696). Frame openly admits that these terms have not solved the problems or answered every question. However, these terms did help the church solidify what it believed against the ever present heresies.
B.B. Warfield, former president of Princeton Theological Seminary, clearly explains how these terms have remained faithful to Scriptural teachings about God,
- "the definition of a Biblical doctrine in such un-Biblical language can be justified only on the principle that it is better to preserve the truth of Scripture than the words of Scripture. The doctrine of the Trinity lies in Scripture in solution; when it is crystallized from its solvent it does not cease to be Scriptural, but only comes into clearer view. Or, to speak without figure, the doctrine of the Trinity is given to us in Scripture, not in formulated definition, but in fragmentary allusions... we are not passing from Scripture, but entering more thoroughly into the meaning of Scripture. We may state the doctrine in technical terms, supplied by philosophical reflection; but the doctrine stated is a genuinely Scriptural doctrine."  In other words, Warfield states that Christians must be faithful to what is in Scripture when we are using non-biblical language.
Augustine made note of this issue, saying "The answer 'three persons' is given, not that something should be said, but so as not to remain wholly silent," (On the Trinity, 5.9.10). We should not be afraid of looking at the whole of Scripture in order to understand who God is. Theologians over time have used terms that better describe the being of God and the persons relationship(s) to one another.
Various terms used in trinitarian language
- See main pages: Essence, Nature, Being, Person, Substance, Homoousios, Homoiousios, Heteroousios, Perichoresis
- The Doctrine of the Trinity in the Early Church (basictheology.com)
- Tracking the Trinity in Contemporary Theology (PDF), by John T. Pless (from the 27th Annual Symposium on the Lutheran Confessions)
- "Trinity" (ISBE) Part 1, Part 2, by B. B. Warfield
- Mormon Theism, the Traditional Christian Concept of God, and Greek Philosophy: A Critical Analysis (pdf), by Francis Beckwith. This article defends Christianity against Mormon objections to using non-biblical language to describe who God is. HTML version