This is the first meaning of our bringing to the altar the elements of our food. For we already know that food is life, that it is the very principle of life and that the whole world has been created as food for man. We also know that to offer this food, this world, this life to God is the initial “eucharistic” function of man, his very fulfillment as man. We know that we were created as celebrants of the sacrament of life, of its transformation into life in God, communion with God.
…To be sure, it is a sacrifice: but sacrifice is the most natural act of man, the very essence of his life. Man is a sacrificial being, because he finds his life in love, and love is sacrificial: it puts the value, the very meaning of life in the other and gives life to the other, and in this giving, in this sacrifice, finds the meaning and joy of life.
From chapter two in For the Life of the World by Alexander Schmemann (34-35).