Not giving up in praying

Metropolitan Anthony writes on the prayer of Bartimaeus (Living Prayer, p. 48):

"How often does it not happen that after seeking and struggling for years on our own, when on a sudden we begin to cry to God, many voices try to silence our prayers, outward voices as well as inward voices. Is it worth praying? How many years did you struggle and God did not care? Is he to care now? What is the use of praying? Go back into your hopelessness, you are blind, and blind for ever. But the greater the opposition, the greater also is the evidence that help is at hand. The devil never attacks us so violently as when we are quite close to the term of our struggle, and we might yet be saved, but often are not, because we give way at the last moment. Give in, says the devil, make haste, it is too much, it is more than you can stand, you can put an end to it at once, do not wait, you cannot endure it any more. And then we commit suicide, physically, morally, spiritually; we renounce the struggle and accept death, just a minute before help was at hand and we might have been saved."