Debate exists as to whether the earliest Church Fathers in Christian history believed in the doctrine of the Trinity – the Christian doctrine that God the Father, the Son (Jesus Christ) and the Holy Spirit are three distinct persons sharing one (essence).
Some of the evidence used to support an early belief in the Trinity consists of triadic statements (referring to the Father, Son and Holy Spirit) from the New Testament and from the writings of the Church Fathers. The view that the Son was "of the substance of the Father, God of God[...] very God of very God" was formally ratified at the First Council of Nicaea in 325 AD. The Holy Spirit was included at the First Council of Constantinople (381 AD), which formally ratified the doctrine of the relationship between the Father, Son and Holy Spirit as one substance () and three co-equal persons ().
Introduction Some Trinitarians say the doctrine of the Trinity was revealed during the time that the New Testament was written; others state that it was revealed in the Patristic period (–451/787 AD). Nontrinitarians, on the other hand, generally state that the traditional doctrine of the Trinity did not exist until centuries after the end of the New Testament period.Jeff Rath, An Appeal to Trinitarian Christians: Historical Background of the Trinity, online (accessed 24/12/2013) Some Trinitarians agree with this, seeing a development over time towards a true understanding of the Trinity.J. N. D. Kelly, Early Christian Doctrines 5th edn (London: A&C Black, 1977), p. 87-88,90 Trinitarians sometimes refer to Christian belief about God before the traditional statements on the Trinity as unsophisticated, 'naive',J. N. D. Kelly, Early Christian Doctrines 5th edn (London: A&C Black, 1977), p. 90 or 'incipient Trinitarianism',M. Turner and G. McFarlane, 'Trinity' in I. H. Marshall (ed.), et al., New Bible Dictionary (3rd edn), electronic edition and that early Christians were 'proto-Trinitarian, partially Trinitarian'.Dale Tuggy, The Lost Early History of Unitarian Christian Theology, paper delivered at CoGGC Theological Conference, Atlanta [May, 2013], 4:43-56 Unitarians and some Trinitarians state that this means that those early Christians were not Trinitarians.Charles Morgridge, The true believer's defence against charges preferred by Trinitarians (1837), p. 162
Expressions which link together the name of the Father, the Son, and the Holy Spirit occurred very early in the History of the Christian Church. These are sometimes taken as expressions about the Trinity. Other times, they are referred to more generally as 'triadic'.J. N. D. Kelly, Early Christian Doctrines 5th edn (London: A&C Black, 1977), p. 88-89 It is stated by some that "these passages cannot immediately be taken as evidence of the belief in the co-substantial unity of God; names may be conjoined for any number of reasons (e.g. unity in greeting, unity of purpose, etc.) so even the use of a threefold formula cannot be conclusive".Thomas Gaston (2007), Proto-Trinity: The Development of the Doctrine of the Trinity in the First and Second Christian Centuries. MPhil(b). Thesis. University of Birmingham, UK. p. 69
Two examples appear in the New Testament: 2 Corinthians 13:13 and Matthew 28:19. The context of 2 Corinthians 13:14 (verse 13 in the Vulgate and the NRSV), which is the close of a letter, suggests the church's conjunction of the Father, Son and Holy Spirit may have originated as a doxological formula; while the context of Matthew 28:19, the Great Commission, shows that the verbal conjunction of the Father, Son, and Holy Spirit was used early on as a baptismal formula. Unitarians hold that "the Father, Son and Holy Spirit are mentioned together [in the New Testament] in the same context, but not in any way that suggests they are all distinct persons who together comprise the totality of God";David Burke, 'The Great Trinity Debate: Week 5: Father, Son and Holy Spirit' available online here and here (accessed 24/12/2013) a "literary triad does not equate to an ontological triunity".David Burke, 'The Great Trinity Debate: Week 5: Father, Son and Holy Spirit. Rebuttal' online (accessed 24/12/2013)
This triadic pattern is even more marked in the glimpses available of the early Church's liturgy and day-to-day catechetical practice.J. N. D. Kelly, Early Christian Doctrines A & C Black 1965 (1965) p.88 Even so, some have said that the "indications from the apostolic and sub-apostolic writers are that [their] triadic formulas[...] do not carry the same significance as post-Nicene triadic formulas". The oldest extant work in which the word "Trinity" itself (Greek ) is used is Theophilus of Antioch's 2nd-century To Autolycus. There it is used to refer to God, his word and his wisdom. The view that the Son was "of the essence of the Father, God of God[...] very God of very God" was formally ratified at the First Council of Nicaea in 325 AD. The Holy Spirit was included at the First Council of Constantinople (381 AD), where the relationship between the Father, Son and Holy Spirit as one substance () and three co-equal persons () was formally ratified.
First century The Didache is thought to use the Gospel of Matthew (although a minority of scholars argue they are independent of one another or that it is Matthew that uses the Didache) only and no other known Gospel, and thus it must have been written before the four-Gospel canon had become widespread in the churches, i.e. before the second half of the 2nd century when Tatian produced the Diatessaron.Date according to Metzger, Bruce. The Canon of the New Testament. 1997 Given its literary dependence on the Gospel of Matthew, it is not surprising that the Didache follows the Gospel of Matthew in designating a triadic formula as the baptismal formula:Thomas Gaston (2007), Proto-Trinity: The Development of the Doctrine of the Trinity in the First and Second Christian Centuries. MPhil(b). Thesis. University of Birmingham, UK. p. 70
Scholars such as Clayton N. Jefford have noted that Jesus is not "ever specifically given a designation of divinity within the text. He is simply called "servant, child" () in the prayers and referenced as "the Lord" () elsewhere." Jefford argues that this may have been for reasons of cultural sensitivity. Specifically towards Jews, as their beliefs on deity (found in the Torah at Deuteronomy 6:4) stand in opposition to belief in a triune God. This allows for a reading of Didache that harmonises fully with the Jewish perspective on God. This allows the reader to come away unoffended, and thus the text can be correctly read without invocation of a triune God.
Some scholars, however, disagree with Jefford's conclusion on cultural sensitivity. They argue that such caution was impossible to exercise as they believe the trinity doctrine had not yet been developed. For example, the Encyclopedia Britannica says of the trinity "The doctrine developed gradually over several centuries". This position would mean it was impossible for Jefford's conclusion on cultural sensitivity to be correct, since these scholars say "It was not until later in the 4th century that the distinctness of the three and their unity were brought together in a single orthodox doctrine of one essence and three persons." However, other scholars disagree with this conclusion and argued that proto-trinitarian formula and teaching can be found there.
Second century
Early second century: Ignatius of Antioch Ignatius, second bishop of Antioch, who was martyred in Rome around 110 AD,Eusebius of Caesarea, Church History iii.36 wrote a series of letters to churches in Asia Minor on his way to be executed in Rome. The conjunction of Father, Son and Holy Spirit appears in his letter to the Magnesian church:
Unitarians argue that Ignatius is not indicating that the Father, the Son and the Spirit "are one substance anymore than he is saying flesh and spirit are one substance".Thomas Gaston (2007), Proto-Trinity: The Development of the Doctrine of the Trinity in the First and Second Christian Centuries. MPhil(b). Thesis. University of Birmingham, UK. p. 72
: Polycarp of Smyrna Polycarp was martyred in Smyrna (where he was also Bishop) in the year 155. It is said by Irenaeus of Lyons that he was a pupil of the Apostle John. In his final prayer before his martyrdom, he "praises, glorifies, and blesses" the Father. He does this "through" Jesus.
169–181: Theophilus of Antioch Theophilus of Antioch's is the oldest extant work that uses the actual word "Trinity" to refer to God, his Word and his Wisdom. The context is a discussion of the first three days of creation in Genesis 1–3:
It is maintained by some that "Theophilus does not use [sic] to mean 'three-in-one', but rather simply uses it to indicate that there were three things before man, God and His Word and His Wisdom";Thomas Gaston (2007), Proto-Trinity: The Development of the Doctrine of the Trinity in the First and Second Christian Centuries. MPhil(b). Thesis. University of Birmingham, UK. p. 74 that he, like other second and third century authors, was referring to "a "trinity", triad or threesome, but not a triune or tripersonal God".
In contrast to Trinitarian theology, Theophilus of Antioch did not view the Son as an eternally self existing person. Theophilus wrote that God "begat Him, emitting Him along with His own wisdom before all things." Instead of speaking of the Word as the Creator, Theophilus speaks of the "Word as a helper in the things that were created by Him", thus he assigns the role of Creator to God alone, while assigning the lesser position of "helper" to the "begat" Son. Many scholars believe this viewpoint is inconsistent with Theophilus believing in a trinity. For example, Dr. Norman Geisler comments: "There are no exceptions; Christ is the Creator of all things including angels and everything visible or invisible. Since Christ could not be both the Creator of everything and at the same time a creature Himself, it is necessary to conclude that He is Himself the uncreated Creator of all creation".Christian Apologetics, 1988, p. 338 It is noteworthy that Theophilus specified that only 1 of the 3 mentioned is God. Even in his most famous quote "Trinity, of God, and His Word, and His wisdom", Theophilus only identifies one of the three as God. The other two are described as being parts or aspects of this God ("His" Word and "His" Wisdom). Neither does Theophilus describe the Word and Wisdom as persons. He simply says "God, then, having His own Word internal within His own bowels, begat Him, emitting Him along with His own wisdom before all things." The viewpoint held by Theophilus of both the Word (whom he later identified as the Son) and God's Wisdom, as both being emitted at some point in time, would seem to conflict with the Trinitarian viewpoint of God being eternal, uncreated, equal and self existing.
Third century: Theology in response to Patripassianism and Sabellianism