Keep Your Attention on the Words of the Prayer
To pray with thought for what the words of the prayer say—is indeed prayer, only limping on one leg. Prayer ceases to be prayer when attention turns away from the words of the prayer. When consciousness is present during prayer—this is prayer, even though unsatisfactory. Feeling will come, but you must also strive for it. It is better to do this through reflecting on the content of prayers outside the time of prayer, and then during the prayer itself stir up your heart. Even better is to ask God Himself that He always warm your heart.
Do also this: when you have gone through all the truths, linger on the last point—the Judgment and the judgment’s decision—awaiting the pronouncement: “Come” or “Depart.” And in that position cry out: “Lord, have mercy!” For once the Lord decides, no one can change it.
(Letter 615. Vol. 4, p. 89)