Isaiah 9:6 For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
John 20:28 And Thomas answered and said unto him, My Lord and my God.
John 20:29 Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed.
IMO, the simplest way to explain the Deity (Trinity) is found in these two scriptures, but yet no one can fully understand the Trinity as that would mean one could fully understand all the complexities of heavens.
Can you fathom the depths of God or discover the limits of the Almighty? They are higher than the heavens, what can you do? Job 11:7, 8; Isaiah 55:9.
Isa 55:8 For my thoughts are not your thoughts, neither are your ways my ways, saith the LORD.
Isa 55:9 For as the heavens are higher than the earth, so are my ways higher than your ways, and my thoughts than your thoughts.
God is the word from the beginning being one God who exist in three persons. Trinity means three in one Spirit, God the Father, God the Son, God the Holy Spirit.
John 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
John 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.
John 14:23 Jesus answered and said unto him, If a man love me, he will keep my words: and my Father will love him, and we will come unto him, and make our abode with him.
John 14:24 He that loveth me not keepeth not my sayings: and the word which ye hear is not mine, but the Father's which sent me.
John 14:25 These things have I spoken unto you, being yet present with you.
John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
John 14:27 Peace I leave with you, my peace I give unto you: not as the world giveth, give I unto you. Let not your heart be troubled, neither let it be afraid.
God is Spirit, Alpha and Omega, the beginning and the end. Jesus also said of Himself in Rev 1:8 I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty.
God is the word (Spirit of God),
The word became flesh (Jesus, Spirit of God) and dwelt among us,
When the word (Jesus, Spirit of God made flesh) ascended back up to heaven, once again God sent His Spirit, (Holy Spirit) to indwell us and teach us all things and bring those things back to our remembrance.
Deity (Trinity) is God's Spirit manifested in the person of Jesus as God's plan of salvation through His birth, death and resurrection before the foundation of the world.
Holy Spirit (God's Spirit) was again sent down to permanently indwell those who are Spiritually born again, John 3:5-7, who will teach us all truths of what Jesus, (the word of God made flesh), already taught His disciples who were sent out into the world to make disciples of all of us to help teach others the Gospel of God's grace through faith.
John 1:10 He was in the world, and the world was made by him, and the world knew him not.
1Co 1:30 But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:
Rom 8:9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
2Cor 13:5 Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?
Col 1:27 To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:
Rev 1:8 I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty.