Dear Gilbert, thank you for your question.
First of all I want to start by telling you that both the Father, Son, and HolySpirit are one. They’re not separated from each other, when Jesus Christ was in the earth bodily, He was the word of God in flesh, the Holy Spirit is the Spirit of God the one that brings God’s presence to us. He was sent to us after Jesus ascended to heaven. When we get to heaven we’re not going to see 3 persons1 (father, Son and HolySpirit) we’ll only see JESUS (The bible says that the FULLNESS OF GODHEAD DWELL IN JESUS BODILY).
So when you’re in fellowship you can say I’m in fellowship with God or Jesus or HolySpirit, you’re simply saying the same thing. Holy Spirit is one of the same kind with God and Jesus (allos parakletos)… HolySpirit is the one sent down to help us function on earth as children of God. His work will be done when we get to heaven