Robert Raines describes the operation of koinonia groups in his church. (religion-online.org)
In this earliest Christian teaching on liturgical participation, the word koinonia which St Paul uses can also be translated quite properly as «communion». (faith.org.uk)
The Willingen Conference (1952) added «the notion of «witness», martyria, as the overarching concept,» saying «This witness is given by proclamation [kerygma], fellowship [koinonia], and service [diakonia].» (religion-online.org)