And so, without any faithless hesitation, we must persevere in our prayers, and never entertain a doubt that by our insistence in prayer we shall obtain all that we ask after God’s Will. For our Lord exhorts us, desiring to put before us those things which are eternal and heavenly that, in a sense, we should compel Him with our importunity, for He not only does not despise or repel the importunate, but rather encourages and praises them, and most graciously promises that He will grant them whatsoever they have with perseverance hoped to attain, saying, ‘Ask and it shall be given you, seek and ye shall find, knock and it shall be opened unto you; for every one that asketh receiveth, and he that seeketh findeth, and to him that knocketh it shall be opened (Matthew 7:7)…and so…let us at least be animated by persevering importunity, which is within the power of all who desire it, without any difficulty of merit or of labor.
~St John Cassian