Prayer is almost as much a mystery as God. Prayer always seems to be more than the words we use to describe it or the ways in which we understand it. Prayer is as old as the human family, stretching all the way back to the fall of Adam and Eve. Prior to disobeying God, our first parents lived in friendship with him. The intimacy they shared precluded the need for prayer. Their sin, however, produced a chasm between themselves and God. Because God created them to share his life, the desire for him not only remained, it also intensified. St. Augustine describes this as a restlessness within the human heart that can only be satisfied by resting in God. We can say, therefore, with a fair degree of certainty that prayer is the action that enables communication between that which is human and that which is divine. Prayer is the means by which human beings seek to access and experience God.
—from the book Prayer Everywhere: The Spiritual Life Made Simple
by Fr. Gary Caster