[G]roups or assemblies formed on the basis of a particular culture, class, profession or age should learn to regard themselves not as Churches, and be taught to seek the experience of the Church only in gatherings where all ages, sexes, professions, cultures etc. meet, for this is what the Gospel promises us to be the Kingdom of God: a place where all the natural and cultural divisions are transcended.

— John D. Zizioulas, Being and Communion, 255.