The term Christian Church expresses the idea of Christianity (the Christian religion) seen in its role as an institution. The phrase "the Church" in its widest sense (as "the Body of Christ") has a similar breadth.
In practice the monolithic "Christian Church" has fragmented almost from its beginnings. Over the centuries many individual Christian churches have emerged, each functioning in their own institutional manner and often viewing each other as sectarian or heretical. Thus definitions of the one "true" Christian Church may vary widely.