According to the Bible there is only one God and he has a Son, Jesus Christ.
In John 17, Jesus prayed the following words:
Father, the hour is come; glorify thy Son, that thy Son also may glorify thee: As thou hast given him power over all flesh, that he should give eternal life to as many as thou hast given him. And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent. I have glorified thee on the earth: I have finished the work which thou gavest me to do. And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was. ~ v.1-5
When the New Testament is surveyed, the overarching truth which comes up again and again is that the One true God is the Father of the Lord Jesus Christ, and Christ is his Son in the fullest sense of the word, having the same divine and eternal nature as the Father. In the text above, Jesus prays to the Father to be glorified with the Father’s own self which is the glory he had before the world was. Christ came from God and has always existed with God and in God. The apostle Paul refers to the deity of Christ as the mystery of godliness.
And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory. ~1 Timothy 3:16
Christ is one with the Father in spirit, being divine, and in his eternal existence having always been with the Father. Jesus came into the world from the Father, who is God.
In 1 Corinthians 8, the apostle Paul declares, For though there be that are called gods, whether in heaven or in earth, (as there be gods many, and lords many,) but to us there is but one God, the Father, of whom are all things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by him. ~ 1 Corinthians 8:5-6
Notice the language Paul uses: One God, the Father of whom are all things… and one Lord Jesus Christ, by whom are all things. This is consistent with Paul’s words elsewhere, that God created all things by Jesus Christ.
Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ; And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ… ~ Ephesians 3:8-9
According to Paul, the unsearchable riches of Christ were hidden in God from the beginning of the world. Christ is indeed the revelation of God’s person who dwells in unapproachable light and whom no man has seen (1 Timothy 6:16). Christ is the revelation of God’s person to fallen humanity.
The writer of Hebrews describes Jesus as the Son by whom God has spoken to us, by whom also God made the worlds. He then declares that Jesus is the brightness of his glory and the express image of his person. ~ Hebrews 1:3
In creation we see God’s outward handiwork, In Christ we see his inward glory and beauty – his love, his grace, his kindness, and his mercy. Christ brings us into fellowship with God and reveals to us his glory by the Holy Spirit.
The Holy Spirit is the Spirit of the One true God who gave his only begotten Son.
But when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak. For it is not ye that speak, but the Spirit of your Father which speaketh in you. ~ Matthew 10:19-20
And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance… But Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judaea, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words: For these are not drunken, as ye suppose, seeing it is but the third hour of the day. But this is that which was spoken by the prophet Joel; And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams: And on my servants and on my handmaidens I will pour out in those days of my Spirit; and they shall prophesy… ~Acts 2:1-4; 14-18
In the texts above Jesus refers to the Holy Spirit as the Spirit of your Father (God), and Peter interprets the Holy Spirit coming on the Day of Pentecost as God pouring out his Spirit. Over and over again, the Holy Spirit is referred to as God’s Spirit.
For God hath not called us unto uncleanness, but unto holiness. He therefore that despiseth, despiseth not man, but God, who hath also given unto us his holy Spirit. ~ 1 Thessalonians 4:7-8
He is also referred to as the Spirit of Christ.
But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his. ~ Romans 8:9
Consider Paul’s words to the Ephesians:
For this cause I bow my knees unto the Father of our Lord Jesus Christ, of whom the whole family in heaven and earth is named, that he would grant you, according to the riches of his glory, to be strengthened with might by his Spirit in the inner man; that Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, may be able to comprehend with all saints what is the breadth, and length, and depth, and height; And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God. ~Ephesians 3:14-19
Paul bows in prayer before the Father of our Lord Jesus Christ, for it is the Father to whom we pray through Christ. Paul says the whole family in Heaven and in earth are named from the Father. He then refers to the Holy Spirit as the Father’s Spirit: that he (the Father) would grant you, according to the riches of his glory, to be strengthened with might by his Spirit in the inner man…
Notice Paul’s expectation of the Father granting strength in our inner man by his Spirit is to this end – that Christ may dwell in our hearts by faith, that we be rooted and grounded in love, that we comprehend the love of Christ in all its vastness, and thus be filled with all the fullness of God.
In Christ the fullness of God is revealed. Through the Spirit Christ dwells in our hearts drawing us close to the glorious God who sent his Son to be the Savior of the world. In Christ, God is revealed to us. Through the Holy Spirit Christ lives in us. This is the fellowship of the mystery we are called into, and thus we come to know the one true God and Jesus Christ whom he has sent.
But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him. But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God. For what man knoweth the things of a man, except the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God. Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God. Which things also we speak, not in the words which man’s wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned. But he that is spiritual judgeth all things, yet he himself is judged of no man. For who hath known the mind of the Lord, that he may instruct him? but we have the mind of Christ. ~ 1 Corinthians 2:9-16