Communion of Saints is With: Each Other
Source: TTT
Galatians 2:9
And recognizing the grace that I had been given, James, Cephas, and John—those reputed to be pillars—gave me and Barnabas the right hand of fellowship, so that we should go to the Gentiles, and they to the circumcised.
1 John 1:3, 7
We proclaim to you what we have seen and heard, so that you also may have fellowship with us. And this fellowship of ours is with the Father and with His Son, Jesus Christ. / But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin.