Why is it that sometimes God doesn't answer His people

Why is it that sometimes God doesn't answer His "phone" when sincere people call Him in prayer? Why did God let poor Job go through that horrible experience when He Himself had to admit that Job was "a perfect and an upright man" (1:8)? Why did He let David for ten long years be hunted in the wilderness like a wild animal when he was "the anointed of the Lord"? Why, when Jeremiah gave himself for service, did God let him suffer a lifetime of anguish (no restitution ever, like Job had!)? Is God fair?
Well, let's try: (1) Job was honored to fight alone in the arena like a gladiator, given the job of defending God in His great controversy with Satan. Stupendous: a human being entrusted with that enormous responsibility--defending God! If Job had done what his dear wife said, "Curse God and die!" he would have proved that Satan is right, and forced God into profound embarrassment before the world and the universe. A terrible battle, but God had no choice: let him go it alone, apparently forsaken. (And the "church" of that day, his three friends, made his hell worse.) Job was a forerunner of Christ, a tremendous honor.
(2) There had to be a "David" so that when the Son of God became the Son of man He could also be "the son of David." David had to go through his experiences of feeling forsaken by God so that Christ could later read his psalms and be strengthened thereby. David "the anointed one" was also a forerunner of Christ. The price? Pain and suffering; but it was worth it.
(3) Jeremiah is now honored as "the greatest of the prophets"; he will have the honor throughout eternity.
(4) God must have "144,000" to honor Him likewise in the last great trials of faith (Rev. 7:1-4; 14:1-5). If He has only 143,999, His word will fail and He will be embarrassed in the great controversy with Satan. Perhaps you are that last one who is so important. Hang on.