'As you borrow your breath from the air and emit it into the air again—so that you are always surrounded by air, and it penetrates you—so also your soul comes from God and will return again to God, so that you are always in God, and are surrounded on all sides and inwardly filled with Him as with air. This is the meaning of the words "filled with the Spirit." As you breathe every minute by means of air, so every minute you are mentally either with God or with the Devil, according to your inward disposition. What air is to the body, the spirit of God is to the soul. As you breathe from the air the elements required to nourish your body, so likewise you breathe into yourself from the Spirit of God good inclinations and thoughts.'
- Saint John of Kronstadt