All rational, spiritual and other qualities of man, distinguishing him from the other creatures, have their focus and ultimate fulfillment in this capacity to bless God, to know, so to speak, the meaning of the thirst and hunger that constitutes his life. 'Homo sapiens,' 'homo faber' ... yes, but, first of all, 'homo adorans.' The first, the basic definition of man is that he is the priest. He stands in the center of the world and unifies it in his act of blessing God, of both receiving the world from God and offering it to God - and by filling the world with this eucharist, he transforms his life, the one that he receives from the world, into life in God, into communion with Him. The world was created as the 'matter,' the material of one all-embracing eucharist, and man was created as the priest of this cosmic sacrament.

alexander schmemann, for the life of the world, ch.1.2, p.15