Dietrich Bonhoeffer on fellowship

Bonhoeffer says:

So between the death of Christ and the Last Day it is only by a gracious anticipation of the last things that Christians are privileged to live in visible fellowship with other Christians. It is by the grace of God that a congregation is permitted to gather visibly in this world to share God's Word and sacrament. Not all Christians receive this blessing. The imprisoned, the sick, the scattered lonely, the proclaimers of the Gospel in heathen lands stand alone. They know that visible fellowship is a blessing. They remember, as the Psalmist did, how they went "with the multitude...to the house of God, with the voice of joy and praise, with a multitude that kept holyday" (Ps. 42.4). But they remain alone in far countries, a scattered seed according to God's will. Yet what is denied them as an actual experience they seize upon more fervently in faith. Thus the exiled disciple of the Lord, John the Apocalyptist, celebrates in the loneliness of Patmos the heavenly worship with his congregations "in the Spirit on the Lord's day" (Rev. 1:10). He sees the seven candlesticks, his congregation, the seven stars, the angels of the congregations, and in the midst and above it all the Son of Man, Jesus Christ, in all the splendor of the resurrection. He strengthens and fortifies him by His Word. This is the heavenly fellowship, shared by the exile on the day of his Lord's resurrection.

Life Together. San Francisco, CA: HarperSanFrancisco. 1954, p. 18-19.