There are many Christians and believers that dispute the "Trinity", although the word "Trinity" is not a biblical word, it can be used to describe the fact that God is three yet one, which might sound like a mystery, but it is very simple to understand. The only thing that hinders the understanding is, that religion, and doctrines have been the point of breakdown in allowing believers to get a grasp of what God is revealing to us, concerning himself and how he does describe himself to us in. How to study the bible

Re:3:14: .................... These things saith The Amen, the Faithful and True witness, the Beginning of the creation of God;

2Co:10:5: Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ;

This is the reason there are so many religions and doctrines out there in the world trying to create "Imaginations" in our minds contrary to who God is.

God reveals himself to man as, Trinity and as One God, consistently through the bible. Whatever God wants us to know, he openly shows us, and who he wants us to focus on, which is also evident why He says either Father or Son or Holy Spirit, Spirit of God or Word of God, the Truth, The Life, The Way, The Alpha, The Omega, the First, The Last, The Beginning, The End, The Resurrection ,etc for a reason, and that being, so we can grow in the knowledge of God and His Goodness with his Greatness, including how he predestined us to be in Christ Jesus and what we have become.

Lets start at the beginning, I will also not try and add my own mind or explanations, so that you can see it from Gods mouth, happy reading.

Ge:1:2: 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.
Ge:1:3: And God said, Let there be light: and there was light.

Here it is evident that God Speaks Words and His Spirit goes out to achieve what he spoke. So every time God speaks, His Spirit the Holy Spirit is performing the spoken Word.

In the next verses we can see God calling himself " Us" and " Our" and "Them" and "Lord to Lord" and "God to God" also his Image. I did cover this in Description of God

Ge:1:26: And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.

Ge:3:22: And the LORD God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever:

Ge:11:7: Go to, let us go down, and there confound their language, that they may not understand one another's speech.

Isa:6:8: Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me.

Ec:12:1: Remember now thy Creator in the days of thy youth, while the evil days come not, nor the years draw nigh, when thou shalt say, I have no pleasure in them;

Psalms:110:1: The LORD said unto my Lord, Sit thou at my right hand, until I make thine enemies thy footstool.

Psalms:45:7: Thou lovest righteousness, and hatest wickedness: therefore God, thy God, hath anointed thee with the oil of gladness above thy fellows.

Isa:48:12: Hearken unto me, O Jacob and Israel, my called; I am he; I am the first, I also am the last.
Isa:48:13: Mine hand also hath laid the foundation of the earth, and my right hand (Jesus) hath spanned the heavens: when I call unto them, they stand up together.
Isa:48:14: All ye, assemble yourselves, and hear; which among them hath declared these things? The LORD hath loved him: he will do his pleasure on Babylon, and his arm shall be on the Chaldeans.
Isa:48:15: I, even I, have spoken; yea, I have called him: I have brought him, and he shall make his way prosperous.
Isa:48:16: 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.

Isa:64:8: But now, O LORD, thou art our father; we are the clay, and thou our potter; and we all are the work of thy hand.

Mal:2:10: Have we not all one father? hath not one God created us? why do we deal treacherously every man against his brother, by profaning the covenant of our fathers?

Joh:8:54: Jesus answered, If I honour myself, my honour is nothing: it is my Father that honoureth me; of whom ye say, that he is your God:
Joh:8:55: Yet ye have not known him; but I know him: and if I should say, I know him not, I shall be a liar like unto you: but I know him, and keep his saying.
Joh:8:56: Your father Abraham rejoiced to see my day: and he saw it, and was glad.

Here we can see The Trinity all three at once Jesus, Holy Spirit, Father

Lu:3:21: Now when all the people were baptized, it came to pass, that Jesus also being baptized, and praying, the heaven was opened,
Lu:3:22: And the Holy Ghost descended in a bodily shape like a dove upon him, and a voice came from heaven, which said, Thou art my beloved Son; in thee I am well pleased.

Jesus taught the Trinity

M't:28:18: And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
M't:28:19: Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
M't:28:20: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.

Joh:8:58: Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.

Joh:10:30: I and my Father are one.

Joh:14:9: Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father?

Joh:14:10: Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works.

Jesus is God

1Tm:3:16: And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.

Joh:1:1: In the beginning was the Word, and the Word was with God, and the Word was God.
Joh:1:2: The same was in the beginning with God.
Joh:1:3: All things were made by him; and without him was not any thing made that was made.
Joh:1:4: In him was life; and the life was the light of men.
Joh:1:14: And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.

Joh:9:37: And Jesus said unto him, Thou hast both seen him, and it is he that talketh with thee.
Joh:9:38: And he said, Lord, I believe. And he worshipped him.

Ti:2:13: Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ;

Heb:1:8: But unto the Son he saith, Thy throne, O God, is for ever and ever: a sceptre of righteousness is the sceptre of thy kingdom.
Heb:1:9: Thou hast loved righteousness, and hated iniquity; therefore God, even thy God, hath anointed thee with the oil of gladness above thy fellows.

Joh:5:18: Therefore the Jews sought the more to kill him, because he not only had broken the sabbath, but said also that God was his Father, making himself equal with God.
Joh:5:19: Then answered Jesus and said unto them, Verily, verily, I say unto you, The Son can do nothing of himself, but what he seeth the Father do: for what things soever he doeth, these also doeth the Son likewise.
Joh:5:20: For the Father loveth the Son, and sheweth him all things that himself doeth: and he will shew him greater works than these, that ye may marvel.

Ro:9:5: Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen.

Ph'p:2:5:Let this mind be in you, which was also in Christ Jesus:
Ph'p:2:6: Who, being in the form of God, thought it not robbery to be equal with God:
Ph'p:2:7: But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men:
Ph'p:2:8: And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross.
Ph'p:2:9: Wherefore God also hath highly exalted him, and given him a name which is above every name:
Ph'p:2:10: That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth;
Ph'p:2:11: And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father.

The Holy Spirit is God

Ac:5:3: 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?

Ac:5:4: 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.

Joh:4:24: God is a Spirit: and they that worship him must worship him in spirit and in truth.

Lu:12:10: And whosoever shall speak a word against the Son of man, it shall be forgiven him: but unto him that blasphemeth against the Holy Ghost it shall not be forgiven.

Ac:13:2: As they ministered to the Lord, and fasted, the Holy Ghost said, Separate me Barnabas and Saul for the work whereunto I have called them.

1Co:3:16: Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?

1Co:6:19: What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own?

2Co:3:17: Now the Lord is that Spirit: and where the Spirit of the Lord is, there is liberty.

Heb:3:7: Wherefore as the Holy Ghost saith, To day if ye will hear his voice,

Apostles taught the Trinity

1Co:12:3: Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.
1Co:12:4: Now there are diversities of gifts, but the same Spirit.
1Co:12:5: And there are differences of administrations, but the same Lord.
1Co:12:6: And there are diversities of operations, but it is the same God which worketh all in all.
1Co:12:7: But the manifestation of the Spirit is given to every man to profit withal.

2Co:13:14: The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Ghost, be with you all. Amen.

1Pe:1:2: Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.

Eph:4:4: There is one body, and one Spirit, even as ye are called in one hope of your calling;
Eph:4:5: One Lord, one faith, one baptism,
Eph:4:6: One God and Father of all, who is above all, and through all, and in you all.
Eph:4:7: But unto every one of us is given grace according to the measure of the gift of Christ.

M't:28:19: Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:

1Jo:5:7: For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.

1Jo:5:3: For this is the love of God, that we keep his commandments: and his commandments are not grievous.
1Jo:5:4: For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.
1Jo:5:5: Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?
1Jo:5:6: This is he that came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth.

I hope you managed to get through this, it is the KEY to understanding all scriptures and all scriptures harmonise with this Knowledge