Romans 10:1-4 KJV
Brethren, my heart's desire and prayer to God for Israel is, that they might be saved.
For I bear them record that they have a zeal of God, but not according to knowledge.
For they being ignorant of God's righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God.
For Christ is the end of the law for righteousness to every one that believeth.

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

The Father, the Word, and the Holy Ghost were all fully in Jesus Christ when He was on earth according to Colossians 2:9 KJV
For in him dwelleth all the fulness of the Godhead bodily.

That's why Jesus said in John 14:9 KJV, he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father?
And about the Holy Ghost, He said in John 14:17 KJV
Even the Spirit of truth; whom the world cannot receive, because it seeth him not, neither knoweth him: but ye know him; for he dwelleth with you, and shall be in you.

And concerning the Word (Jesus), the scripture says in
John 1:1-4,10-11,14 KJV
In the beginning was the Word, and the Word was with God, and the Word was God.
[2] The same was in the beginning with God. [3] All things were made by him; and without him was not any thing made that was made.
[4] In him was life; and the life was the light of men.
[10] He was in the world, and the world was made by him, and the world knew him not.
[11] He came unto his own, and his own received him not.
[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.

The Word was made flesh in the person of Jesus Christ, our Lord and Saviour. He was the full manifestation of the Godhead in a bodily form.