The following is an excerpt from a book I read while I was at the Prayer Mountain in June of 1991. I wrote them in my journal but forgot to write down the source or reference. If my recollection serves me right, I believe the author is E.M. Bounds (but it can also be D.L. Moody or A.W. Tozer)
Prayer produces cleanliness of heart and purity of life. It can produce nothing else. Unrighteous conduct is born in prayerlessness. the two go hand in hand. Prayer and sinning cannot keep company with each other. One, or the other, must of necessity, stop. get men to pray, and they will quit sinning, because prayer creates a distaste for sinning. It works so much upon the heart, that evil-doing becomes repugnant.
We pray feebly, because we live feebly. the stream of prayer cannot rise higher than the fountain of living. The force of the prayer closet is made up of the energy which flows from the flowing streams of life. The weakness of living grows out of the shallowness of character.
Feebleness of living reflects its weakness in the praying hours. We simply cannot talk strongly, intimately, and confidently to God unless we are living for Him, faithfully and truly. Te prayer closet cannot become sanctified to God when life is alien to His laws and purpose. We must learn His lesson well. Righteous character and Chrsitanlike conduct give us a peculiar and preferential standing in prayer before God.