It's not. All the original God-models were formulated with variations of maintaining Monotheism while including the Lord Jesus Christ. This was a long and varied process that was largely to refute and contrast against various forms of Gnosticism and both ancient and newer forms of Polytheism and Henotheism, as well as Pantheism and Panentheism.
Unitarianism, Binitarianism, Trinitarianism, Tritheism, Arianism, and Sabellianism were all well-developed conceptual understandings of the Hebrew Echad in the 1st and 2nd centuries AD. By the 3rd century, there was conflict that ultimately led to the First Ecumenical Council in the eatly 4th century in Nicea (325AD). Some held to the Deity of Christ as a procreative act within the Virgin, differing on various issues regarding such as the nature of each "person's" substance. Others considered the overshadowing by the Holy Ghost to be a creative act similar to Adam in Eden, making Jesus fully man as non-ontological Deity by identity rather than by nature. Unitarianism is one of the latter, obviously.
Unis believe the Holy Spirit is simply the Spirit of God, since they hold that God is a singular entity. Jesus is a special-creation man by Virgin Birth, and His identity perfectly represents God; but He is not Deity by any sharing of Divine substance in His nature. Jesus was born as a man and died as a man; and He is now transended to heaven in a glorified body, delegated all Divine authority by God. But He is not God.
That's why Unis refer to "Jesus' God". He is a (glorified) man, and God is His God.
(Modern American Unis are predominantly NOT what I described above. They are Universalists who believe in Conditional Immortality, Annihilationism, and many varied other non-biblical teachings. Many are very New Age and even Occultish. The above would be describing "Biblical" Unitarianism.)
Unitarianism, Binitarianism, Trinitarianism, Tritheism, Arianism, and Sabellianism were all well-developed conceptual understandings of the Hebrew Echad in the 1st and 2nd centuries AD. By the 3rd century, there was conflict that ultimately led to the First Ecumenical Council in the eatly 4th century in Nicea (325AD). Some held to the Deity of Christ as a procreative act within the Virgin, differing on various issues regarding such as the nature of each "person's" substance. Others considered the overshadowing by the Holy Ghost to be a creative act similar to Adam in Eden, making Jesus fully man as non-ontological Deity by identity rather than by nature. Unitarianism is one of the latter, obviously.
Unis believe the Holy Spirit is simply the Spirit of God, since they hold that God is a singular entity. Jesus is a special-creation man by Virgin Birth, and His identity perfectly represents God; but He is not Deity by any sharing of Divine substance in His nature. Jesus was born as a man and died as a man; and He is now transended to heaven in a glorified body, delegated all Divine authority by God. But He is not God.
That's why Unis refer to "Jesus' God". He is a (glorified) man, and God is His God.
(Modern American Unis are predominantly NOT what I described above. They are Universalists who believe in Conditional Immortality, Annihilationism, and many varied other non-biblical teachings. Many are very New Age and even Occultish. The above would be describing "Biblical" Unitarianism.)