1 Kings 19:15 And the LORD said unto him, Go, return on thy way to the wilderness of Damascus: and when thou comest, anoint Hazael to be king over Syria:
16 And Jehu the son of Nimshi shalt thou anoint to be king over Israel: and Elisha the son of Shaphat of Abelmeholah shalt thou anoint to be prophet in thy room.
Elisha had been running away from vengeful Jezebel, running for his life (1 Kings 19:1-3).
He had faced the devil and was apparently defeated.
There, at Beersheba, God started a fresh set of lessons for Elijah, lessons on withstanding all that the devil could want to throw at him.
First, He sent heavenly food to strengthen Elijah.
Then He let Elijah go to Mount Horeb, where God had met with the nation of Israel as they came out from under slavery to Egypt and her false gods.
There the Lord spoke to Elijah and asked him what he was doing there. After Elijah narrated briefly his piteous condition, God sent a great and strong mountain-tearing, rock-crushing wind. Then He sent an earthquake. Finally He sent a rock.
Then the Lord spoke again, in a still small voice, and asked the same question, which Elijah answered with the same piteous narrative.
But then the Lord declared that Elijah had passed the test!
And God sent Elijah out with a history-changing mission, a mission to anoint a new king over Syria, a new king over Israel, and a great prophet who would follow in Elijah's steps and do greater works than Elijah did!
Elijah had thought his usefulness was over. He wanted God to end his life (1 Kings 19:4).
But God had not finished with Elijah. Instead of taking his life, God sent him forth with a new commission, to do better things than he had ever done before!
If you think the devil has won a great victory and rendered you useless to God ... if you have retired to a cave of despondency ... God wants to speak to you there. He wants to tell you what to do ... where to go ... and He wants to bring you out.
Pause before the Lord. Hear what He has to say to you. Then shake off the bondages of fear and depression. Leave the cave!
Let the anointing flow!
Further reading: Elijah versus Jezebel.