Are you praying for a "hopeless" situation? I learned something about this kind of praying by comparing some of the battles of the Israelites.
Judah drove out the inhabitants of the mountain, but they "could not drive out the inhabitants of the valley, because they had chariots of iron," Judges 1:19. When Judah was brought to face these chariots of iron, they hesitated, wavered, gave way to fear, and lost their faith in God. Then there was no driving out the enemy. They decided it was hopeless and lost heart.
But were the iron chariots really the reason for their failure? We might think so if it had not been that Joshua and Barak had conquered despite iron chariots. (See Joshua 4:9 and Judges 4:15.) They refused to give up because, while they could not defeat iron chariots, God could. They kept their focus on God.
Have you met up with the "impossible iron chariots" in your praying? We might be tempted to think of some reason God "couldn't possibly answer" and believe that if it were not for a certain factor or situation, we could trust God for victory. But when we get to Heaven we'll not be able to say, "Lord, I would have conquered my discouragement and doubts if it had not been for those "iron chariots." When in eternity we glimpse God's glorious power and faithfulness to answer persevering prayer, we'll see that our excuses made no sense.
Thank You, Lord, for the hope I have in You.
"Jesus looked at them and said, 'With man this is impossible, but not with God; all things are possible with God'" (Mark 10:27).