We have God's authority to ask and expect to receive when the motives are correct. We must believe that God wants to bless us, and until God individually convicts someone that His plan is otherwise, we are not to accept failure. Tribulation brings about proven character. Don't withdraw because of failure. Learn from it.
Perseverance is a characteristic much lacking in Christianity today.
Some Christians who fail get defeated and feel like God has abandoned them. Some despair to the point of depression or suicide. One of God's principles is persistence in the face of discouragement. Anyone would do God's will if God would prove Himself first. Paul said that now we see dimly, as through a mirror, and therefore our spiritual vision will be imperfect.