And why is it taught by the Church?
Because it is Scriptural.
Okay, you seem to think you are very logical, so here is the test.
If the Trinity doctrine is Scriptural why is it that non-Trinitarian Christians who are reading the SAME scriptures do not adhere to the Trinity doctrine?
The article below explains why the Trinity doctrine came to be taught by the Church. I suggest you learn some Church history.
The largest nontrinitarian Christian denominations are
The Church of Jesus Christ of Latter-day Saints,
Oneness Pentecostals,
Jehovah's Witnesses, La Luz del Mundo and the Iglesia ni Cristo, though there are a number of other smaller groups, including Christadelphians, Church of the Blessed Hope, Christian Scientists, ...
Nontrinitarianism - Wikipedia
Now don't run away.
Please answer the question and address what it says in the article below (
red emphasis mine).
Which Christian denominations do not believe in the Trinity? Why not?
The Jehovah’s Witnesses, the Church of Jesus Christ of LDS, Iglesia Ni Cristo, Christadelphians, Christian Scientists, Dawn Bible Students, Living Church of God, Oneness Pentecostals, Members Church of God International, Unitarian Universalist Christians, The Way International, The Church of God International, the United Church of God, and Armstrongism do not believe in trinitarinanism because they do not share history with the post-apostolic process that concocted the doctrine. Also, Unitarians believe that the Father is the sole deity and the Savior was not God.
Virtually all other Christian denominations believe in the 3-in-1 Trinity because of the influence from Roman Catholicism.
The seeds of trinitarian ideas were fabricated over the course of centuries following Jesus' death and came into vogue in the 4th century AD when Emperor Constantine, an unbaptized pagan, threw his weight behind it for political reasons. After decades of controversy and much bloodshed over the issue, the doctrine of trinitarianism was made official by the Council of Constantinople 381AD. By then, there were no 12 apostles living to contradict it. (I redacted “Athanasian Creed” from this paragraph in response to Francis Mardsden’s comment.)
Trinitarianism is not Biblical - just the opposite. Jesus said, The Father is greater than the Son. (John 14:28) That alone explodes the trinitarian myth. Also, all three godhead members were manifested separately at Christ’s baptism; Jesus in the river, the Father's voice from heaven, and the Spirit descending like a dove. (Matthew 3:16-17) On many occasions, Jesus prayed to His Father with words that prove they were two distinct individuals, Jesus conforming His will to the Father’s. The risen Lord told Mary He had yet to visit His Father. Jesus claimed not to know when the end would come and said only His Father knew. (Mark 13:32) Jesus said, The Son will judge but not the Father. (John 5:22) He said, blasphemy against Him and the Father was forgivable but not against the Holy Ghost. On the cross, He asked His Father why He had forsaken Him. (Mt. 27:46) “After the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God.” (Mk. 16:19) As Stephen was being stoned, he looked into heaven and saw “Jesus standing on the right hand of God.” (Acts 7:55)
These are but a few examples of Jesus teaching and demonstrating that He was separate and distinct from His Father.
The references in the Bible declaring the Father and the Son to be “one” are explained by Christ Himself in His intercessory prayer in the Garden of Gethsemane where He asked His Father to help the disciples to become “one” even as He and the Father were one. The Bible says a husband and wife become “one flesh” but nobody suspects that marriage transforms a couple of humans into an incomprehensible binity. (Mark 10:8) Unity of mind and purpose is a common theme in life.
Only extremely twisted logic allows a person to believe in a Jesus who is also His own Father conceived by His own Holy Ghost self! Trinitarianism pollutes the true character of the godhead and contradicts the scripture that "God created man in his own image" as we are not triple-personality nor composite individuals. Trinitarianism hyper-mystifies God, unnecessarily distancing us from the Father of our spirits while depersonalizing our Savior by denying Him of His distinct individuality.
Even those who believe it have trouble explaining it, invoking obscure terminologies that the average person finds foreign and obfuscational. “God is three consubstantial persons or hypostases.” The Athanasian Creed repeats the same theme multiple times, as if verbosity stabilizes the nonsense. “We worship one God in Trinity, and Trinity in Unity; Neither confounding the Persons; nor dividing the Essence. For there is one Person of the Father; another of the Son; and another of the Holy Ghost. But the Godhead of the Father, of the Son, and of the Holy Ghost, is all one; the Glory equal, the Majesty coeternal. Such as the Father is; such is the Son; and such is the Holy Ghost.
The Father uncreated; the Son uncreated; and the Holy Ghost uncreated. The Father unlimited; the Son unlimited; and the Holy Ghost unlimited. The Father eternal; the Son eternal; and the Holy Ghost eternal. And yet they are not three eternals; but one eternal. As also there are not three uncreated; nor three infinites, but one uncreated; and one infinite. So likewise the Father is Almighty; the Son Almighty; and the Holy Ghost Almighty. And yet they are not three Almighties; but one Almighty. So the Father is God; the Son is God; and the Holy Ghost is God. And yet they are not three Gods; but one God.” And so on and on and on.
The question should be rephrased, “Which Christian sects hold to trinitarianism and why?”
Which Christian denominations do not believe in the Trinity? Why not? - Quora
