Jesus prayed that we might know God and Jesus Christ:
“And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.” (John 17:3)
To get a clear understanding, one should always look at the context. Who is the audience? What is the occasion? The audience is the Father, the occasion is Jesus looking forward to the Cross; His death, resurrection and ascension. Knowing He was going to be leaving the company of His friends.
The second thing is, this particular verse is considered to have been added by the author of John, or perhaps even later, as nowhere in the NT does Jesus ever refer to Himself as “Jesus Christ”. He always references Himself in relationship to the Father as Son. Such as "Son of Man, “Son of God”, “My Father”, etc.When referencing Himself scripture always uses first person pronoun, “I”, “Me”, “My”.
So, this verse is considered a third person addition. A statement of belief, from an author, which is in harmony with first person statements of Jesus, such as later in John 20:
21 [Jesus] said to them again, “Peace be with you.
As the Father has sent me, so I send you.”
John 17:3 Now this is eternal life, that they should know you, the only true God,
and the one whom you sent, Jesus Christ.
Both express the teaching of Jesus and the Apostle’s that Jesus is sent by the Father. Verse 3 is not a first person expression with ontological implications.
If we then continue in John 17 to verse 6:
“I revealed your name to those whom you gave me out of the world. They belonged to you, and you gave them to me, and they have kept your word."
Which is seen in light of an earlier point in the Gospel of John, chapter 8, where Jesus reveals the name of God that was given to Moses, “I AM”, several times and ultimately references the name of God to Himself.
58 "Jesus said to them,“Amen, amen, I say to you, before Abraham came to be, I AM.”
Further, if we look to what John 17:6 again:
“I revealed your name to those whom you gave me out of the world. They belonged to you, and you gave them to me, and they have kept your word."
Jesus reveals to the world God’s name, and in so doing reveals Himself as the Word of God. There is distinction between the Father and Son, as they are distinct Person’s. There is One God, Who Jesus reveals as “I AM”, saying that He is the name of God (I AM) revealed. When looked at in light of John 1:1,
In the beginning was the Word,
and the Word was with God,
and the Word was God.
We undertand that Jesus Himself is God’s Word, revealed.
One’s word is not something that exists separate from you. If you give your word about something, you are giving something of yourself, something that when the person who has received your word, views it is distinct from you “I have your word”, but not separate from you (you are held to your word). You are not your word and your word is not you, but when you give your word, you are giving a part of yourself.
As Christians, we begin our understanding of God with Jesus Christ, as He reveals Himself, and the Father. The Father and Son reveal the Holy Spirit. The Holy Spirit testifies of Jesus Christ. Put in the context of the Old Testament, which teaches us there is One God, we then accept by Faith what God has revealed about Himself. God is three Persons. God is One. This is what scripture teaches.
Scripture does NOT teach that God is three separate Gods, among a council of who knows how many Gods. That belief is a result of human imagination and conscience formed outside of Apostolic teaching.