If we eat, we eat to the Lord, to gain physical energy to enable us to do what pleases Him. And if we fast, we fast to the Lord to strengthen the spirit and form a strong relationship with God. Then the energy of the body is for Him and the strength of the spirit is for Him. Exactly as the Apostle said: “Glorify God in your body and in your spirit, which are God’s” (1 Cor 6:20).
—H.H. Pope Shenouda III, The Spiritual Man