Hypostasis (philosophy and religion) in the context of "Nontrinitarianism"

In Christian theology, the incarnation is the belief that the pre-existent divine person of Jesus Christ, God the Son, the second person of the Trinity, who is also the Logos (Koine Greek for 'word'), was "made flesh" by being conceived through the power of the Holy Spirit in the womb of a woman, the Virgin Mary, who is also known as the Theotokos (Greek for "God-bearer" or "Mother of God"). The doctrine of the incarnation then entails that Jesus was at the same time both fully God and fully human.

In the incarnation, as traditionally defined by those Churches that adhere to the Council of Chalcedon, the divine nature of the Son was united but not mixed with human nature in one divine person, Jesus, or according to those adhering to the Council of Ephesus, the divine and human natures of Christ are fully united into one composite nature "without mixing, confusion, or separation". This is central to the traditional faith held by most Christians. Alternative views on the subject (see Ebionites and the Gospel of the Hebrews) have been proposed throughout the centuries, but all were rejected by Nicene Christianity.

The Trinity (Latin: Trinitas, lit. 'triad', from trinus 'threefold') is a Christian doctrine concerning the nature of God, which defines one God existing in three coeternal, consubstantial divine persons: God the Father, God the Son (Jesus Christ) and God the Holy Spirit, three distinct persons (hypostases) sharing one essence/substance/nature (homoousion).

Hypostatic union (from the Greek: ὑπόστασις hypóstasis, 'person, subsistence') is a technical term in Christian theology employed in mainstream Christology to describe the union of Christ's human nature and divine nature in one composed hypostasis, or individual personhood.

In the most basic terms, the concept of hypostatic union states that Jesus Christ is both fully God and fully man. He is simultaneously perfectly divine and perfectly human, having two complete and distinct natures at once.

The pre-existence of Christ asserts the existence of Christ prior to his incarnation as Jesus. One of the relevant Bible passages is John 1 (John 1:1–18) where, in the Trinitarian interpretation, Christ is identified with a pre-existent divine hypostasis (substantive reality) called the Logos (Koine Greek for "word" or "reason"). There are nontrinitarian views that question the aspect of personal pre-existence, the aspect of divinity, or both.

In many Gnostic belief systems, there exist various emanations of God, who is known by such names as One, Monad, Aion teleos (αἰών τέλεος "The Broadest Aeon"), Bythos (βυθός, "depth" or "profundity"), Arkhe (ἀρχή, "the beginning"). In Gnosticism these emanations of God are named as Proarkhe (προαρχή, "before the beginning") and as Aeons (which are also often named and may be paired or grouped). In different systems these emanations are differently named, classified, and described (but emanation is common to all forms of 'Gnosticism'). In Basilidian Gnosis they are called sonships (υἱότητες huiotetes; sing.: υἱότης huiotes); according to Marcus, they are numbers and sounds; in Valentinianism they form male/female pairs called syzygies (συζυγίαι, from σύζυγοι syzygoi: lit. "yokings together").

This source of all being is an Aeon, in which an inner being dwells, known as Ennoea (ἔννοια, "thought, intent"), Charis (χάρις, "grace") or Sige (σιγή, "silence"). The split perfect being conceives the second Aeon, Nous (Νους, "mind"), within itself. Complex hierarchies of Aeons are thus produced, sometimes to the number of thirty. These Aeons belong to a purely ideal, noumenal, intelligible, or supersensible world; they are immaterial, they are hypostatic ideas. Together with the source from which they emanate, they form Pleroma (πλήρωμα, "fullness"). The lowest regions of Pleroma are closest to darkness; that is, the physical world.

In Christianity, the doctrine of the Trinity states that God is a single essence in which three distinct hypostases ("persons"): the Father, the Son, the Holy Spirit, exist consubstantially and co-eternally as a perichoresis. Islam considers the concept of any "plurality" within God to be a denial of monotheism. Monotheism in Islam, known as Tawhid, is the religion's central and single most important concept, upon which a Muslim's entire religious adherence rests. Shirk, the act of ascribing partners to God – whether they be sons, daughters, or other partners – is considered to be a form of unbelief in Islam and is considered the worst sin in Islam. The Quran repeatedly and firmly asserts God's absolute oneness, thus ruling out the possibility of another being sharing his sovereignty or nature. In Islam, the Holy Spirit is believed to be the angel Gabriel. Muslims have explicitly rejected Christian doctrines of the Trinity from an early date.