Historically the nature of God has been referred to as the Trinity. This means that the Father, the Son and the Holy Spirit are 3 separate persons which constitute only one God. The word "Trinity" is not in the Bible. This simply is the name of a doctrine or idea that is taught in the Bible. Usually people that do not believe the doctrine of the Trinity  define it incorrectly. Then they set out to prove that the false definition is un-biblical, which of course it is because they incorrectly defined it. Let me try to explain it as clear as I can. God the Father is called God, but this does not mean that he is Jesus, nor does it mean that he is the Holy Spirit. The Father is called God in Rom 1:7 "to all who are beloved of God in Rome, called as saints: Grace to you and peace from God our Father and the Lord Jesus Christ". Jesus the Son is called God, but this does not mean that he is the Father nor does it mean he is the Holy Spirit. Jesus is called God in  John 1:1&14
(1) In the beginning was the Word, and the Word was with God, and the Word was God.
(14) And the Word became flesh, and dwelt among us, and we beheld His glory, glory as of the only begotten from the Father, full of grace and truth. (Notice this states that God became flesh. In the context this is Jesus. See also Phil.2:5-8)

John 20:27-29 Then He said to Thomas, "Reach here your finger, and see My hands; and reach here your hand, and put it into My side; and be not unbelieving, but believing." Thomas answered and said to Him, "My Lord and my God!" Jesus said to him, "Because you have seen Me, have you believed? Blessed are they who did not see, and yet believed."    (Notice Jesus did not rebuke Peter when he called him Lord and God. The conclusion is Jesus is God the Son.)

          The Holy Spirit is called God but this does not mean that he is the Father nor does it mean that he is Jesus. The Holy Spirit is called God In Acts 5:3-4 But Peter said, "Ananias, why has Satan filled your heart to lie to the Holy Spirit, and to keep back some of the price of the land? "While it remained unsold, did it not remain your own? And after it was sold, was it not under your control? Why is it that you have conceived this deed in your heart? You have not lied to men, but to God."
(Notice Peter stated they lied to the Holy Spirit. Then in the next breath he states that this was God they lied to.)

Heb 3:7-11 Therefore, just as the Holy Spirit says, "Today if you hear His voice, Do not harden your hearts as when they provoked Me, as in the day of trial in the wilderness, Where your fathers tried me by testing me, and saw My works for forty years. "Therefore I was angry with this generation, and said, 'They always go astray in their heart; and they did not know My ways'; As I swore in My wrath, 'they shall not enter My rest.'"
(Notice we are told that the Holy Spirit is the one that says he was provoked and swore in his wrath "they shall not enter my rest".)