In 2021, Kimbanguism celebrated its centenary since the appearance of the prophet Simon Kimbangu. In the same year, they were expelled from the World Council of Churches (WCC). What happened? What theological positions did the first African-initiated member church of the WCC take to make this happen? This work explores these and other questions, using field research from Congo and archival materials from the WCC to analyse the historical as well as theological developments of this religious grouping in its first hundred years. The author develops a six-stage model to show how the genesis of a new religion is fostered and how a new religious formation emerges from a mother religion.