Fellowship is a supernatural grace that causes Christians to love one another deeply. It is a manifestation of the indwelling Holy Spirit. Just as the Spirit’s dunamis power enables us to heal the sick or work miracles, His koinonia (fellowship) knits our hearts and binds us together.
After the outpouring of the Spirit in Acts 2, koinonia caused the early disciples to share their possessions unselfishly (vv. 44–45) and to share meals often (v. 46). Many people decided to become Christians when they witnessed this loving community (v. 47).
Koinonia (fellowship) held the early Christians together in the face of persecution and caused them to lay down their lives for one another. It is still essential in the church today. But we can’t download it or fake it.
To have the relational Christianity of the Book of Acts, we have to invite the Holy Spirit to do His work of connecting us with our brothers and sisters in Christ with His supernatural bond of koinonia.
"They devoted themselves to the apostles’ teaching and to fellowship, to the breaking of bread and to prayer." (Acts 2:42)