2 But whence has he hoped for this? Since, he says, “He has inclined His ear unto me: and in my days I have called upon Him”. I loved, therefore, because He will hear; He will hear, “because He has inclined His ear unto me.” But whence do you know, O human soul, that God has inclined His ear unto you, except you say, “I have believed”? These three things, therefore, “abide, faith, hope, charity:” because you have believed, you have hoped; because you have hoped, you have loved....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)