Does Believing in the Trinity Mean Accepting Extra-Biblical Authority?

First of all, it is not hard to prove that the Bible teaches God is a Trinity.

Jesus Christ is God.

Acts 20:28: “Take heed therefore unto yourselves, and to all the flock, over the which the Holy Ghost hath made you overseers, to feed the church of God, which he hath purchased with his own blood.”

Titus 1:3-4: “But hath in due times manifested his word through preaching, which is committed unto me according to the commandment of God our Savior (my note- whom Jesus is about to be labelled as- continuing on); To Titus, mine own son after the common faith: Grace, mercy, and peace, from God the Father and the Lord Jesus Christ our Savior.”

Jesus is also not the Father.

Jesus says in John 6:38: “For I came down from heaven, not to do mine own will, but the will of him that sent me.”

Matthew 26:36-39: “Then cometh Jesus with them unto a place called Gethsemane, and saith unto the disciples, Sit ye here, while I go and pray yonder. And he took with him Peter and the two sons of Zebedee, and began to be sorrowful and very heavy. Then saith he unto them, My soul is exceeding sorrowful, even unto death: tarry ye here, and watch with me. And he went a little farther, and fell on his face, and prayed, saying, O my Father, if it be possible, let this cup pass from me: nevertheless not as I will, but as thou wilt.”

The Bible also calls the Holy Spirit God. It is seen in Acts chapter 5 that Ananias was lying to God by lying to the Holy Spirit.

Acts 5:1-4: “But a certain man named Ananias, with Sapphira his wife, sold a possession, And kept back part of the price, his wife also being privy to it (i.e. knowledgeable of it), and brought a certain part, and laid it at the apostles’ feet. But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.”

It is also clear that the Holy Spirit is neither Jesus nor the Father. Jesus clearly told His disciples on the night before He was crucified that He would leave the world, go to the Father, and then send the Holy Spirit.

John 15:26: “But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:”

The Father, the Son, and the Holy Spirit are also demonstrated to be distinct from each other in many other Bible passages such as John 16:7-11, Acts 1:1-8, Acts 2:32-36, Acts 5:30-32, and Romans 8:13-17.

The following Biblical event even clearly illustrates the Trinity.

Matthew 3:16-17: “And Jesus, when he was baptized, went up straightway out of the water: and, lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him: And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.”

Are there even proofs of the Trinity in the Old Testament (i.e. the Tanakh)? Yes.

Isaiah 48:16-17: “Come ye near unto me, hear ye this; I have not spoken in secret from the beginning; from the time that it was, there am I: and now the Lord God, and his Spirit, hath sent me. Thus saith the Lord, thy Redeemer, the Holy One of Israel; I am the Lord thy God which teacheth thee to profit, which leadeth thee by the way that thou shouldest go.”

Note that the Redeemer in the preceding verses is the Holy One of Israel who was sent by the Lord God and His Spirit.

Genesis 1:1-3: “In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters. And God said, Let there be light: and there was light.”

We see the Trinity in the opening verses of the Bible because Jesus is the Word whom all things were created by.

John 1:1-3: “In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him; and without him was not any thing made that was made.”

Some are against using the word “trinity” to describe God because the word is not found in the Bible. However, a trinity is simply “a group of three people or things.” The definition of trinity fits the description which the Bible gives of the Godhead.

The writers of the Bible would speak of God in reference to God the Father while speaking of Christ and the Holy Spirit as distinct, co-equal persons. They were careful to distinguish the persons within the Trinity. They also simultaneously emphasized the unity of God in order to give no one just occasion to claim that they were teaching polytheism.

Since calling God a Trinity is warranted due to what the whole counsel of the Bible teaches, one does not have to accept the councils of the Catholic Church or any other authority outside of the Bible in order to believe that God is a Trinity. He existed as a Trinity before the Council of Nicaea. It would be right to describe Him as a Trinity even if the Catholic Church had concluded otherwise.

This topic is also proof that even though the Catholic Church, the Orthodox Church, mainstream Protestantism, and mainstream Evangelical Christianity (all of which affirm the Trinity) are each wrong about many things, they are also not wrong on everything. Though truth demands divergence from any and all these in many ways, simply believing the total opposite of any of these is by no means a sure way to discern truth. That would rather be another means to go into serious error.