Trinity

== Early Christianity ==
{{further|Trinitarianism in the Church Fathers}}

===Before the Council of Nicaea===
[[File:Dogmatic sarcophagus.JPG|thumb|right|Detail of the [[Early Christian art and architecture|earliest known artwork]] of the Trinity, the [[Dogmatic Sarcophagus|Dogmatic or Trinity Sarcophagus]], {{circa}} 350 ([[Vatican Museums]])

Three similar figures, representing the Trinity, are involved in the creation of [[Eve]], whose much smaller figure is cut off at lower right; to her right, [[Adam]] lies on the ground{{sfn|Milburn|1991|p=68}}]]

While the developed doctrine of the Trinity is not explicit in the books that constitute the [[New Testament]], it was first formulated as early Christians attempted to understand the relationship between Jesus and God in their scriptural documents and prior traditions.{{sfn|Hurtado|2005|pp=644–648}}

An early reference to the three "persons" of later Trinitarian doctrines appears towards the end of the first century, where [[Clement of Rome]] rhetorically asks in his [[First Epistle of Clement|epistle]] as to why corruption exists among some in the Christian community; "Do we not have one God, and one Christ, and one gracious Spirit that has been poured out upon us, and one calling in Christ?" (1 Clement 46:6).<ref>Ehrman, Bart D. ''The Apostolic Fathers''. Vol. 1. Loeb Classical Library, 2003, 119. Ehrman further notes (fn. 97) Clement is alluding to Ephesians 4:4–6. Also see 1 Clement 58:2.</ref> A similar example is found in the first century [[Didache]], which directs Christians to "baptize in the name of the Father and of the Son and of the Holy Spirit".<ref>Ehrman, Bart. ''The Apostolic Fathers'', Vol. 1. Harvard University Press, 2003, pp. 411, 429.</ref>

[[Ignatius of Antioch]] similarly refers to all three persons around AD 110, exhorting obedience to "Christ, and to the Father, and to the Spirit".<ref name="ignatius"/> Though all of these early sources do reference the three persons of the Trinity, none articulate full divinity, equal status, or shared being as elaborated by Trinitarians in later centuries.{{citation needed|date=September 2022}}

The pseudonymous [[Ascension of Isaiah]], written sometime between the end of the first century and the beginning of the third century, possesses a "proto-trinitarian" view, such as in its narrative of how the inhabitants of the sixth heaven sing praises to "the primal Father and his Beloved Christ, and the Holy Spirit".{{sfn|Hurtado|2005|pp=595–599}}

[[Justin Martyr]] (AD 100 – c. 165) also writes, "in the name of God, the Father and Lord of the universe, and of our Saviour Jesus Christ, and of the Holy Spirit".<ref name="first-apology"/> Justin Martyr is the first to use much of the terminology that would later become widespread in codified Trinitarian theology. For example, he describes that the Son and Father are the same "being" ({{lang|grc-Latn|ousia}}) and yet are also distinct faces ({{lang|grc-Latn|prosopa}}), anticipating the three persons ({{lang|grc-Latn|hypostases}}) that come with [[Tertullian]] and later authors. Justin describes how Jesus, the Son, is distinguishable from the Father but also derives from the Father, using the analogy of a fire (representing the Son) that is lit from its source, a torch (representing the Father).{{sfn|Hurtado|2005|pp=646}} At another point, Justin Martyr wrote that "we worship him [Jesus Christ] with reason, since we have learned that he is the Son of the living God himself, and believe him to be in second place and the prophetic Spirit in the third" (1 Apology 13, cf. ch. 60).

[[File:Albrecht Dürer - Adoration of the Trinity (Landauer Altar) - Google Art Project.jpg|thumb|left|The ''Adoration of the Trinity'' by [[Albrecht Dürer]] (1511)

From top to bottom: Holy Spirit (dove), God the Father and Christ on the cross]]
The first of the early Church Fathers to be recorded using the word "Trinity" was [[Theophilus of Antioch]] writing in the late 2nd century. He defines the Trinity as God, his Word ({{lang|la|Logos}}) and his Wisdom ({{lang|la|Sophia}})<ref name="theophilus2"/> in the context of a discussion of the first three days of creation, following the early Christian practice of identifying the Holy Spirit as the Wisdom of God.<ref>Theophilus, ''To Autolycus'', 1.7 Cf. Irenaeus, ''Against Heresies'', 4.20.1, pg. 3<br>''Demonstration of the Apostolic Preaching'', pg. 5</ref>

The first defense of the doctrine of the Trinity was by [[Tertullian]], who was born around 150–160 AD, explicitly "defined" the Trinity as Father, Son, and Holy Spirit and defended his theology against [[Praxeas]],<ref name="tertullian"/> although he noted that the majority of the believers in his day found issue with his doctrine.<ref name="against-praxeas1"/>

[[File:Bartolomé Esteban Murillo - The Heavenly and Earthly Trinities - 1681-82.jpg|thumb|The "Heavenly Trinity" joined to the "[[Holy Family|Earthly Trinity]]" through the [[Incarnation (Christianity)|Incarnation]] of the [[God the Son|Son]]–''[[The Heavenly and Earthly Trinities]]'' by [[Bartolomé Esteban Perez Murillo|Murillo]] (c. 1677)]]

St. Justin and Clement of Alexandria referenced all three persons of the Trinity in their [[Doxology|doxologies]] and [[Basil of Caesarea|St. Basil]] likewise, in the evening lighting of lamps.{{sfn|Mulhern|1967|p=205}}

[[Origen of Alexandria]] (AD 185 – c. 253) has often been interpreted as [[Subordinationist]] – believing in shared divinity of the three persons but not in co-equality. (Some modern researchers have argued that Origen might have actually been anti-Subordinationist and that his own Trinitarian theology inspired the Trinitarian theology of the later [[Cappadocian Fathers]].){{sfn|Ramelli|2011a}}{{sfn|Barnard|1970|pp=172–188}}

The concept of the Trinity can be seen as developing significantly during the first four centuries by the [[Church Fathers]] in reaction to theological interpretations known as [[Adoptionism]], [[Sabellianism]], and [[Arianism]]. Adoptionism was the belief that Jesus was an ordinary man, born of Joseph and Mary, who became the Christ and Son of God at his baptism. In 269, the [[Synods of Antioch]] condemned [[Paul of Samosata]] for his Adoptionist theology, and also condemned the term {{lang|grc-Latn|[[homoousios]]}} ({{lang|grc|ὁμοούσιος}}, "of the same being") in the modalist sense in which he used it.{{sfn|Chapman|1913}}

Among the [[Nontrinitarianism#Beliefs|nontrinitarian beliefs]], [[Sabellianism]] taught that the Father, the Son, and the Holy Spirit are essentially one and the same, the difference being simply verbal, describing different aspects or roles of a single being.{{sfn|Chadwick|1993|p=87}} For this view Sabellius was excommunicated for [[Heresy#Christianity|heresy]] in Rome c. 220.

=== First Council of Nicaea (325) ===
{{Main|First Council of Nicaea}}
[[File:Glória de São Nicolau - António Manuel da Fonseca (Igreja de São Nicolau, Lisboa), cropped.png|left|thumb|''The Glory of Saint Nicholas'', by [[António Manuel da Fonseca]]; [[Saint Nicholas|Nicholas of Myra]], a participant in the First Council of Nicaea, achieves the [[beatific vision]] in the shape of the Holy Trinity.]]
In the fourth century, [[Arianism]], as traditionally understood,{{efn |name=Arius}} taught that the Father existed prior to the Son who was not, by nature, God but rather a changeable creature who was granted the dignity of becoming "Son of God".{{sfn|Cross|Livingstone|2005|p=100}} In 325, the [[First Council of Nicaea]] adopted the Nicene Creed which described Christ as "God of God, Light of Light, very God of very God, begotten, not made, being of one substance with the Father", and the "Holy Ghost" as the one by which "[[Incarnation (Christianity)|was incarnate]]&nbsp;... of the [[Virgin birth of Jesus|Virgin Mary]]".<ref>{{cite web|url=http://www.ccel.org/ccel/schaff/creeds1.iv.iii.html|title=Creeds of Christendom, with a History and Critical notes |volume=I. The History of Creeds |website=Christian Classics Ethereal Library}}</ref><ref>{{cite web|url=http://www.creeds.net/ancient/niceneg.htm|title=The Nicaeno-Constantinopolitan Creed|first=Michael|last=Anderson |website=creeds.net}}</ref> ("the [[Logos#Christianity|Word]] was made flesh and dwelled among us"). About the Father and the Son, the creed used the term {{lang|grc-Latn|homoousios}} (of one substance) to define the relationship between the Father and the Son. After more than fifty years of debate, {{lang|grc-Latn|homoousios}} was recognised as the hallmark of orthodoxy, and was further developed into the formula of "three persons, one being".

The Confession of the First Council of Nicaea, the Nicene Creed, said little about the Holy Spirit.<ref name="BEoWR"/> At the First Council of Nicea (325) all attention was focused on the relationship between the Father and the Son, without making any similar statement about the Holy Spirit. In the words of the creed:

{{blockquote|We believe in one God, the Father Almighty, Maker of all things visible and invisible. And in one Lord Jesus Christ, the Son of God, begotten of the Father [the only-begotten; that is, of the essence of the Father, God of God,] Light of Light, very God of very God, begotten, not made, being of one substance with the Father; ... And [we believe] in the Holy Ghost. ...}}

===First Council of Constantinople (381)===
{{Main|First Council of Constantinople}}
Later, at the [[First Council of Constantinople]] (381), the Nicene Creed would be expanded, known as Niceno-Constantinopolitan Creed, by saying that the Holy Spirit is worshiped and glorified together with the Father and the Son ({{lang|grc|συμπροσκυνούμενον καὶ συνδοξαζόμενον}}), suggesting that he was also consubstantial with them:

{{blockquote|We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible. And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds (æons), Light of Light, very God of very God, begotten, not made, being of one substance with the Father; ... And in the Holy Ghost, the Lord and Giver of life, who proceedeth from the Father, who with the Father and the Son together is worshiped and glorified, who spake by the prophets ...<ref>See [http://www.ccel.org/ccel/schaff/creeds1.iv.iii.html Creeds of Christendom].</ref>}}

The doctrine of the divinity and personality of the Holy Spirit was developed by Athanasius in the last decades of his life.{{sfn|Hornblower|Spawforth|Eidinow|2012|p=193}} He defended and refined the Nicene formula.<ref name="BEoWR" /> By the end of the 4th century, under the leadership of [[Basil of Caesarea]], [[Gregory of Nyssa]], and [[Gregory of Nazianzus]] (the [[Cappadocian Fathers]]), the doctrine had reached substantially its current form.<ref name="BEoWR"/>

===Middle Ages===
Gregory of Nazianzus, Gregory of Nyssa, and Basil the Great account for the Trinity saw that the distinctions between the three divine persons were solely in their inner divine relations. There are not three gods, God is one divine Being in three persons.<ref>{{ cite book |last1=Shelley |first1=Bruce L. |title=Church History in Plain Language|pages= 113 |year=2013}}</ref> Where the Cappadocian Fathers used social analogies to describe the triune nature of God, Augustine of Hippo used psychological analogy. He believed that if man is created in the image of
God, he is created in the image of the Trinity. Augustine's analogy for the Trinity is the memory, intelligence, and will in the mind of a man. In short, Christians do not have to think of three persons when they think of God; they may think of one person.<ref>{{ cite book |last1=Shelley |first1=Bruce L. |title=Church History in Plain Language|pages= 113 |year=2013}}</ref>

In the late 6th century, some Latin-speaking churches added the words "and from the Son" ({{lang|la|[[Filioque]]}}) to the description of the procession of the Holy Spirit, words that were not included in the text by either the Council of Nicaea or that of Constantinople.<ref>For a different view, see e.g. [http://www.ccel.org/ccel/schaff/npnf214.x.xvi.xi.html Excursus on the Words πίστιν ἑτέραν]</ref> This was incorporated into the liturgical practice of Rome in 1014.<ref>{{cite book |title=Greek and Latin Traditions on Holy Spirit |url=http://www.ewtn.com/library/CURIA/PCCUFILQ.HTM |access-date=18 January 2019}}</ref> {{lang|la|Filioque}} eventually became one of the main causes for the [[East–West Schism]] in 1054, and the failures of the repeated union attempts.

Gregory of Nazianzus would say of the Trinity, "No sooner do I conceive of the One than I am illumined by the splendour of the Three; no sooner do I distinguish Three than I am carried back into the One. When I think of any of the Three, I think of Him as the Whole, and my eyes are filled, and the greater part of what I am thinking escapes me. I cannot grasp the greatness of that One so as to attribute a greater greatness to the rest. When I contemplate the Three together, I see but one torch, and cannot divide or measure out the undivided light."<ref>Gregory of Nazianzus, ''Orations'' 40.41</ref>

Devotion to the Trinity centered in the French monasteries at Tours and Aniane where [[Benedict of Aniane]] dedicated the abbey church to the Trinity in 872. Feast days were not instituted until 1091 at [[Cluny Abbey|Cluny]] and 1162 at Canterbury and papal resistance continued until 1331.{{sfn|Mulhern|1967|p=205}}