Christian theology

=====Person of Christ=====
{{Main|Person of Christ}}
[[File:Christology Flowchart.PNG|thumb|500px|The various Christological positions, and their names]]
;Only divine?
[[Docetism]] (from the Greek verb ''to seem'') taught that Jesus was fully divine, and his human body was only illusory. At a very early stage, various Docetic groups arose; in particular, the [[Gnosticism|gnostic]] sects which flourished in the 2nd century AD tended to have Docetic theologies. Docetic teachings were attacked by [[St. Ignatius of Antioch]] (early 2nd century), and appear to be targeted in the canonical [[Epistles of John]] (dates are disputed, but range from the late 1st century among traditionalist scholars to the late 2nd century among critical scholars).

The Council of Nicaea rejected theologies that entirely ruled out any humanity in Christ, affirming in the [[Nicene Creed]] the doctrine of the [[Incarnation]] as a part of the doctrine of the [[Trinity]]. That is, that the second person of the Trinity became incarnate in the person [[Jesus]] and was fully human.

;Only human?
{{See also|Jewish Christianity}}
The early centuries of Christian history also had groups at the other end of the spectrum, arguing that Jesus was an ordinary mortal. The [[Adoptionists]] taught that Jesus was born fully human, and was adopted as [[Son of God|God's Son]] when [[John the Baptist]] baptised him<ref>{{Bibleverse||Mark|1:10}}</ref> because of the [[Ministry of Jesus|life he lived]]. Another group, known as the [[Ebionites]], taught that Jesus was not God, but the human [[Moshiach]] (messiah, anointed) prophet promised in the [[Hebrew Bible]].

Some of these views could be described as [[Unitarianism]] (although that is a modern term) in their insistence on the oneness of God. These views, which directly affected how one understood the Godhead, were declared [[heresies]] by the Council of Nicaea. Throughout much of the rest of the ancient history of Christianity, Christologies that denied Christ's divinity ceased to have a major impact on the life of the church.

;How can he be both?
:;What sort of divinity?
{{Main|Arianism}}

[[Arianism]] affirmed that Jesus was divine, but taught that he was nevertheless a created being (''there was [a time] when he was not [in existence]''), and was therefore less divine than God the Father. The matter boiled down to one iota; Arianism taught ''[[Homoiousia|Homo'''i'''ousia]]''—the belief that Jesus's divinity is ''similar'' to that of God the Father—as opposed to ''[[Homoousia]]''—the belief that Jesus's divinity is the ''same'' as that of God the Father. [[Arius]]' opponents additionally included in the term ''Arianism'' the belief that Jesus's divinity is ''different'' from that of God the Father (''Heteroousia'').

Arianism was condemned by the Council of Nicea, but remained popular in the northern and western provinces of the empire, and continued to be the majority view of western Europe well into the 6th century. Indeed, even the Christian legend of Constantine's death-bed baptism involves a bishop who, in recorded history, was an Arian.

In the modern era, a number of denominations have rejected the Nicene doctrine of the Trinity, including the [[Christadelphians]] and the [[Jehovah's Witnesses]].<ref>{{Cite book|author=Bruce Milne|title=Know the Truth|publisher=Inter-Varsity Press|pages=181–182|isbn=0-8308-1793-X|year=1999}}</ref>

;What sort of amalgamation?
The Christological debates following the Council of Nicaea sought to make sense of the interplay of the human and divine in the person of Christ while upholding the doctrine of the Trinity. [[Apollinaris of Laodicea]] (310–390) taught that in Jesus, the divine component took the place of the human ''[[nous]]'' (''thinking''– not to be confused with ''[[thelis]]'', meaning ''intent''). This however was seen as a denial of Jesus's true humanity, and the view was condemned at the [[First Council of Constantinople]].

Subsequently, [[Nestorius]] of Constantinople (386–451) initiated a view that effectively separated Jesus into two persons—one divine and one human; the mechanism of this combination is known as ''hypostas'''e'''s'', and contrasts with ''hypostas'''i'''s''—the view that there is no separation. Nestorius' theology was deemed heretical at the [[First Council of Ephesus]] (431). Though, as seen by the writings of [[Babai the Great]], the Christology of the [[Church of the East]] is highly similar to that of Chalcedon, many orthodox Christians (particularly in the West) consider this group to be the perpetuation of [[Nestorianism]]; the modern Assyrian Church of the East has at times shunned this term, as it implies acceptance of the entire theology of Nestorius.

Various forms of [[Monophysitism]] taught that Christ only had one nature: that the divine had either dissolved ([[Eutychianism]]), or that the divine joined with the human as one nature in the person of Christ ([[Miaphysitism]]). A notable monophysite theologian was [[Eutyches]] ({{circa|380}}–456). [[Monophysitism]] was rejected as [[Christian heresy|heresy]] at the [[Council of Chalcedon]] in 451, which affirmed that Jesus Christ had two natures (divine and human) joined in one person, in [[hypostatic union]] (see [[Chalcedonian creed]]). While Eutychianism was suppressed into oblivion by the Chalcedonians and Miaphysites, the Miaphysite groups who dissented from the Chalcedonian formula have persisted as the [[Oriental Orthodox Church]].

As theologians continued to search for a compromise between the Chalcedonian definition and the [[Monophysites]], other Christologies developed that partially rejected the full humanity of Christ. [[Monothelitism]] taught that in the one person of Jesus there were two natures, but only a divine will. Closely related to this is [[Monoenergism]], which held to the same doctrine as the Monothelites, but with different terminology. These positions were declared [[Christian heresy|heresy]] by the [[Third Council of Constantinople]] (the Sixth [[Ecumenical Council]], 680–681).