What is Early Christian?Early Christianity, the period of Christianity preceding the First Council of Nicaea in 325 AD. This typically divides historically into the Apostolic Age and the Ante-Nicene Period (from the Apostolic Age until Nicea). The first Christians, as described in the first chapters of the Book of Acts, were all Jews either by birth or conversion and historians refer to them as Jewish Christians. The early Gospel message spread orally, probably originally in Aramaic, and later in Greek. The New Testament's Acts of the Apostles and Epistle to the Galatians record that the first Christian community centered on Jerusalem and that its leaders included Peter, James, the brother of Jesus, and John the Apostle.
What is Unitarian?Unitarianism can be viewed as a form of Nontrinitarianism which is a form of Christianity that rejects the mainstream Christian doctrine of the Trinity. The teaching that God is three distinct hypostases or persons who are coeternal, coequal, and indivisibly united in one being, or essence (from the Greek ousia). Certain religious groups that emerged during the Protestant Reformation have historically been known as antitrinitarian, but are not considered Protestant in popular discourse due to their nontrinitarian nature. According to churches that consider the decisions of ecumenical councils final, Trinitarianism was definitively declared to be Christian doctrine at the 4th-century ecumenical councils, that of the First Council of Nicaea (325 AD), which declared the full divinity of the Son, and the First Council of Constantinople (381 AD), which declared the divinity of the Holy Spirit. In terms of number of adherents, nontrinitarian denominations comprise a minority of modern Christianity. The largest nontrinitarian Christian denominations are The Church of Jesus Christ of Latter-day Saints ("Mormons") and Jehovah's Witnesses.
What is Trinity?The Christian doctrine of the Trinity (Latin: trinus "threefold") holds that God is one God, but three coeternal consubstantial persons or hypostases. These being the Father, the Son (Jesus Christ), and the Holy Spirit - as "one God in three Divine Persons". The three Persons are distinct, yet are one "substance, essence or nature" (homoousios).