God fills heaven and earth. (Jeremiah 23:24)
He created heaven for the Son to dwell and govern all things. (Matthew 28:18)
But the Son humbled Himself and became a man to serve His Father eternally. (Philippians 2:5-8)
Hence, the One and Only God who came to the world as a man (John 1:18) is Jesus Christ.
At that time, the Holy Spirit came upon Him and had fellowship with the Father. (John 14:20)
The Holy Spirit also spoke to Him and enabled Him to do His work. (John 12:49)
In the same way, the Lord Jesus sent the Holy Spirit who came from the Father to us. (John 15:26) The Holy Spirit came to facilitate fellowship between God and us.
If it is not by the Holy Spirit, we cannot have fellowship with God (1 John 2:1); the Holy Spirit wants to help us in accordance with the will of God. (Romans 8:26)
The fellowship of the Holy Spirit is intended to provide the eternal life of God (Luke 23:46) even to human beings.
When God has fellowship with humanity by the Holy Spirit, He allows human beings to experience bliss. (Matthew 12:28)
Only those people who have fellowship with God in the Holy Spirit can live by the power of God. (Judah 1:20)