An almost universal belief among (post Nicea-Constantinople) Christians is that the God of the Bible is a Trinity of three divine Persons called God the Father, God the Son, and God the Holy Spirit; each Person individual and distinct, yet fully God: co-equal, co-eternal, and possessing all the same attributes of deity.
Even so, there are not three Gods, but one God.
Those puzzled by this mathematical Mystery may well wonder: What did Jesus have to say about the Trinity and whom did he identify as God?
In John 17:1-3 Jesus prayed,
“Father,… this is everlasting life, that they know You the only true God, and Jesus Christ whom You have sent.”
In English the pronoun you can refer to one person or to more than one person. However, the language Jesus spoke and the language in which this was recorded have a singular [one person] form and a plural [more than one person] form for the pronoun you. Here the singular form is used. Jesus addressed this prayer to his Father, used the singular form of the pronoun, and described this one person as “THE ONLY TRUE GOD.” Thus, according to Jesus HIS FATHER ALONE IS GOD! [1] Neither here nor anywhere else in Scripture did he say anything about God’s being a Trinity.
In fact, nowhere does the Bible say that God is a Trinity. Trinitarians can only infer their doctrine by sewing together a tapestry of proof-texts. However, these texts of Scripture can be understood in ways that do not imply that doctrine, and, more importantly, do not contradict Jesus’ statement that his Father is the only true God. Consequently, a scriptural examination of trinitarian arguments is in order to clarify the relationship between the Father, the Son, and the Holy Spirit.
[1] With this Paul agrees; he wrote at 1 Corinthians 8:6, “…yet for us there is one God, the Father, from whom are all things and for whom we exist…” and at Ephesians 4:4-6, “There is… one God and Father of us all, who is above all and through all and in all.” See also Romans 1:7; 1 Corinthians 1:3; 2 Corinthians 1:2, 3; Galatians 1:1, 3, 4; Ephesians 1:2, 3; Philippians 1:2; Colossians 1:2, 3. In all these verses — and more could be cited — the terms “God” and “Father” are equated.