Christian theologyChristian theology is the theology of Christian belief and practice. Such study concentrates primarily upon the texts of the Old Testament and of the New Testament, as well as on Christian tradition. Christian theologians use biblical exegesis, rational analysis and argument.
AdoptionismAdoptionism, also called dynamic monarchianism, is an early Christian nontrinitarian theological doctrine, subsequently revived in various forms, which holds that Jesus was adopted as the Son of God at his baptism, his resurrection, or his ascension. How common adoptionist views were among early Christians is debated, but it appears to have been most popular in the first, second, and third centuries. Some scholars see adoptionism as the belief of the earliest followers of Jesus, based on the epistles of Paul and other early literature.
UnitarianismUnitarianism () is a Nontrinitarian branch of Christianity. Unitarian Christians affirm the unitary nature of God as the singular and unique creator of the universe, believe that Jesus Christ was inspired by God in his moral teachings and that he is the savior of humankind, but he is not comparable or equal to God himself. Unitarianism was established in order to restore "primitive Christianity before [what Unitarians saw as] later corruptions setting in"; Likewise, Unitarian Christians generally reject the doctrine of original sin.
NontrinitarianismNontrinitarianism is a form of Christianity that rejects the mainstream Christian theology of the Trinity—the belief that God is three distinct hypostases or persons who are coeternal, coequal, and indivisibly united in one being, or essence (from the Ancient Greek ousia). Certain religious groups that emerged during the Protestant Reformation have historically been known as antitrinitarian.