Let us always desire the happy life from the Lord God and always pray for it. But for this very reason we turn our mind to the task of prayer at appointed hours, since that desire grows lukewarm, so to speak, from our involvement in other concerns and occupations. We remind ourselves through the words of prayer to focus our attention on the object of our desire; otherwise, the desire that began to grow lukewarm may grow chill altogether and may be totally extinguished unless it is repeatedly stirred into flame.
Therefore, when the Apostle says: Let your petitions become known before God, this should not be taken in the sense that they are in fact becoming known to God who certainly knew them even before they were made, but that they are becoming known to us before God through submission and not before men through boasting.
from today’s Office of Readings, an excerpt from a letter to Proba by St Augustine