Remember God more often than you breathe, says St Gregory of Nazianzus (d. 389). Prayer is more essential to us, more an integral part of ourselves, than the rhythm of our breathing or the beating of our heart. Without prayer there is no life. Prayer is our nature. As human persons we are created for prayer just as we are created to speak and to think. The human animal is best defined, not as a logical or tool-making animal or an animal that laughs, but rather as an animal that prays, a eucharistic animal, capable of offering the world back to God in thanksgiving and intercession.
–Bishop Kallistos of Diokleia