I love the vivid images medieval mystics use to describe God and prayer. A case in point is the writing of the English mystic Walter Hilton. In his treatise providing instruction on prayer and the contemplative life, Hilton writes a beautiful passage likening prayer to fire:
If you pray in this way, you can pray well: for prayer is nothing else than a mounting desire of the heart into God through withdrawal from every earthly thought. And this is why it is compared with a fire, which by its own nature mounts from the earth, always up into the air. In just the same way, your desire in prayer, when it is touched and illumined by that spiritual fire which is God, by nature always mounts to Him from Whom it came.
Notice that Hilton, in the last line of the passage, emphasizes that our desire to pray to God always comes from God.
Walter Hilton (c. 1340 – 1396) was an Augustinian canon and a mystic. He was the first person to write a treatise on mysticism in the English language.