Q. I cannot find the word Trinity in the Bible.
A. That is because the word “Trinity” is not found in the Bible. The Doctrine of the Trinity was formulated in order to explain and synthesize diverse scriptures. To be brief, for instance in the very first book of the Bible:
Genesis 1:26 Then God said, “Let us make man in our image, …
After the revelations of Jesus in the NT we see this verse as signifying the Blessed Trinity. But it was a very subtle hint.
John 8:58 Jesus said to them, “Truly, truly, I say to you, before Abraham was born, I am.”
Jesus claims preexistence and claims for himself THE NAME OF GOD given to Moses in
Ex.3: 13 Then Moses said to God, “Behold, I am going to the sons of Israel, and I will say to them, ‘The God of your fathers has sent me to you.’ Now they may say to me, ‘What is His name?’ What shall I say to them?” 14God said to Moses, “I AM WHO AM“; and He said, “Thus you shall say to the sons of Israel, ‘I AM has sent me to you.'”
Matthew 11:27 “All things have been committed to me by my Father. No one knows the Son except the Father, and no one knows the Father except the Son and those to whom the Son chooses to reveal him.
Jesus claims to be the Son of God. A son is of the same exact nature as the father therefore Jesus is divine, the second person of the Blessed Trinity and in Matthew.
Matthew 28:19 Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit,
Again we have here an allusion to Trinity-One God in Three persons—because “name” is singular followed by three names.