The Church is the sacrament of the Kingdom—not because she possess divinely instituted acts called "sacraments," but because first of all she is the possibility given to man to see in and through this world the "world to come," to see and to "live" it in Christ. It is only when in the darkness of this world we discern that Christ has already "filled all things with Himself" that these things, whatever they may be, are revealed and given to us full of meaning and beauty. A Christian is the one who, wherever he looks, finds Christ and rejoices in Him. And this joy transforms all his human plans and programs, decisions and actions, making all his mission the sacrament of the world's return to Him who is the life of the world.

— For the Life of the World by Alexander Schmemann (Page 113)