Jesus prayed to his Father and identifies his Father as the only true God:

Father.... this is eternal life, that they may know You, the Only True God and Jesus Christ whom You sent.

The Only True God, Jesus' Father, sent Jesus. In Mark chapter 12, there is an interesting exchange between the Jew Jesus and a Jewish scribe:

And one of the scribes came up and heard them disputing with one another, and seeing that he answered them well, asked him, "Which commandment is the first of all?" Jesus answered, "The first is, "Hear, O Israel: The Lord our God, the Lord is one; and you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength.' The second is this, "You shall love your neighbor as yourself.' There is no other commandment greater than these." And the scribe said to him, "You are right, Teacher; you have truly said that He is one, and there is no other but He; and to love him with all the heart, and with all the understanding, and with all the strength, and to love one's neighbor as oneself, is much more than all whole burnt offerings and sacrifices." And when Jesus saw that he answered wisely, he said to him, "You are not far from the kingdom of God." And after that no one dared to ask him any question.

Now let us stop for a moment and ask ourselves a very important question. Just who was this Jewish scribe talking about when he said, "HE is one" and "there is no other but HE"? Is it reasonable to suggest this scribe had a three person being in mind? Or is it more reasonable to suggest he had one person in mind?

[The Pharisees]: "We have one Father: God." (John 8:41).

The Jews never perceived God to be anything but one person. It would be ridiculous to claim this Jewish scribe had anyone but one person in mind. Jesus confirms this fact:

Jesus answered, "If I glorify myself, My glory is nothing; it is My Father who glorifies Me, of whom you say, "He is our God (John 8:54).

Jesus confirms that his Father was the God of the Jews. Jesus too was a Jew. Now notice how Jesus responds to the Jewish scribe.

And the scribe said to him, "You are right, Teacher; you have truly said that He is one, and there is no other but He; and to love him with all the heart, and with all the understanding, and with all the strength, and to love one's neighbor as oneself, is much more than all whole burnt offerings and sacrifices." And when Jesus saw that he answered wisely, he said to him, "You are not far from the kingdom of God."

Jesus wasn't a Trinitarian either. Both the Jewish scribe and Jesus the Jew had the same idea in mind when they said that God is one - Jesus' Father, one person.

Now it gets even more interesting. Notice how the Jesus said, "The Lord our God the Lord is one" and the Jewish scribe responsed to that statement by saying, "you have truly said that He is one, and there is no other but He." Clearly, the Jewish scribe is emphasizing the exclusivity of the God which they have in mind. He says that Jesus had just said "there is no other but He" indicating this is what the Shema is supposed to indicate. And Jesus confirms this fact by saying he had answered wisely. We find the same idea at Deuteronomy 4:35. We must ask, "there is no other but WHO exactly"? Who did Jesus and this Jewish Scribe have in mind exactly? The honest and reasonable person knows the answer.

Jesus' God was his Father and his Father alone. And it is for this reason that we find Jesus teaching his disciples:

"I am ascending to my Father and your Father, to my God and your God" (John 20:17).

The God of Abraham, Isaac, and Jacob was one person, Jesus' Father (Acts 3:13). Jesus' God was his Father. Our God is Jesus' Father. Jesus taught us the truth explicitly when he said, "my God and your God." Let us not serve a different God than Jesus.

Do you thus requite the Lord, you foolish and senseless people? Is not he your Father, who created you, who made you and established you?....See now that I, even I, am he, and there is no God besides ME (Deuteronomy 32:6.29).