Webster defines “fellowship” as “a community of interest, activity, feeling or experience.” The definition makes me think immediately of the Apostle Paul. His desire for fellowship with the Lord Jesus was so strong that he wanted to pass through death, if that shared experience would enable him to know the Lord Jesus better.
God created us so that He might have creatures to love. But He did not stop there. He wanted a creature He could have fellowship with, so He made us in His likeness. Then He came down in the cool of the day to visit. Sin destroyed the fellowship. But that did not change His heart. He sent His Son to do the needed work to reconcile us to Himself so that fellowship could be restored and maintained in a bond of peace.
The Son became a man to make peace by the blood of His cross, and He remains a man so that God and man may remain together forever in the closest bond of fellowship — so that God might “tabernacle” with men.
In turn, God has called man from His lost condition in a world that knows not God into the fellowship of His Son, and as God’s assembly to enjoy and walk together in their common interest in Christ and His glory. As He and the Father are one, so the Son desires “that they all may be one; as Thou, Father, art in Me, and I in Thee, that they also may be one in Us.”