Increasing Our Faith When Discouraged

I Kings 19:3-4, 9
3 And when he saw that, he arose, and went for his life, and came to Beersheba, which belongeth to Judah, and left his servant there.
4 But he himself went a day's journey into the wilderness, and came and sat down under a juniper tree: and he requested for himself that he might die; and said, It is enough; now, O LORD, take away my life; for I am not better than my fathers.
9 And he came thither unto a cave, and lodged there; and, behold, the word of the LORD came to him, and he said unto him, What doest thou here, Elijah?