Prophet Elisha sent the son of another prophet to Ramothgilead in order to anoint Jehu, the son of Jehoshaphat and grandson of Nimshi as king over  Israel. The son of the prophet does as he is told. He pours oil on the head of Jehu and anoints Jehu as king, during which time the prophet conveys to Jehu, the mission that the Lord had for Jehu. The mission that was given to Jehu was to annihilate and smite all of the household of Ahab as a means to avenge the blood of the prophets that Ahab and his wife, Jezebel had spilled (2 Kings 9:1-12). Upon his anointing as king by the Lord, we learn that the people who were with Jehu accept him as king over them as well (2 Kings 9:13).

Jehu started out by killing Jehoram (also known as Joram), son of Ahab and Jezebel (2 Kings 9:14-26) in Jezreel. He then pursued Ahaziah, the son of Jehoram and Athaliah, daughter of Ahab (2 Kings 9:27-28), to Gur near Ibleam and smote him there. Ahaziah fled to Megiddo and died there. Then Jehu returned to Jezreel and solicited the help of two or three eunuchs to throw Jezebel, the wife of Ahab down from the window from which she questioned, if Jehu had come in peace after calling him the murderer of his master, Ahab (2 Kings 9:31). The eunuchs throw Jezebel down and she is killed and eaten by dogs as was prophesied against her by prophet Elijah, for his wickedness and evil against God’s prophets (2 Kings 9:30-37). Jehu then turns his attention to the seventy sons of Ahab in Samaria and has the people of the land slaughter them and send their heads to him in Jezreel (2 Kings 10:1-11). He then goes to Samaria and on his way there, comes across relatives of Ahaziah (and hence of Ahab’s household) and he kills them all (2 Kings 10:12-14). Upon arriving in Samaria he slaughters all that remained of the house of Ahab, as was prophesied by the prophet Elijah (2 Kings 10:17). He then turns his attention to Baal, and the worshipers of Baal, whom Ahab worshiped. Subtly he conspires and acts to be a servant of Baal to gather all the worshipers of Baal and gathers them in the temple of Baal where he appoints eighty men to slaughter all the worshipers of Baal, after ensuring that there were none in that gathering who were worshipers of the LORD (2 Kings 10:18-28). Of Jehu, it is said, that he was the destroyer of Baal from Israel (2 Kings 10:28). And the LORD said unto Jehu, “Because thou hast done well in executing that which is right in mine eyes, and hast done unto the house of Ahab according to all that was in mine heart, thy children of the fourth generation shall sit on the throne of Israel.” (2 Kings 10:30).

However, Jehu did not heed to walk in the law of the Lord with all his heart and did not depart from the sins of Jeroboam, which was idol worship. Jeroboam, the king of Israel (Northern kingdom) erected golden calves in Bethel and Dan and appointed priests to offer sacrifices unto them, for fear that his people would return to worshiping the one and true God, Jehovah, in the Temple of Jerusalem and ultimately return to Judah (Southern kingdom) (1 Kings 13:34). Prophet Hosea prophesies referring to these events, that God would avenge the blood of Jezreel upon the house of Jehu and cause to cease the kingdom of the house of Israel (Hosea 1:4). Why would God do this? Did not Jehu remove the idolatory of Baal from Jezreel? Jehu is guilty of murder for having destroyed the worshipers of Baal while he himself was an idol worshiper of the golden calves. Had he heeded to the God’s law that you shall not have any others gods before me or you shall not make any idols (Exodus 20:3-4), Jehu would not have to been guilty of bloodshed of other idolators. Jehu reigned in Israel for twenty-eight years.

What can we learn from Jehu?
Jehu was anointed with oil on his head, and he followed the mission that God had ordained for him, which was to remove the evil king Ahab’s household from the land. Jehu was a zealous man for the Lord. In fact, in his visit to Samaria, as he is on the mission to annihilate Ahab’s household, he meets Jehonadab, the Rechabite and expresses his zeal for the LORD (2 Kings 10:16). In his mind, Jehu did what was expected of him to do, but his heart was not totally upright before God. Jesus said, you must love the Lord your God with all your heart, all your soul, all your strength and all your mind (Luke 10:27). Jehu loved the Lord with all his mind, which is evident from the zeal he had for the Lord, but Jehu did not love the Lord with all his heart for he gave place for the golden calves (idols) in his heart. He destroyed the idols on the outside, but he failed to destroy the idols within him. Many a times, we act like Jehu as well. We are zealous for the Lord and intellectually we are willing to fight and serve God, but when it comes to the matters of the heart, we uphold the idols of power, prosperity, pleasure, position and popularity in our hearts. Let us not be Jehu, who came to be the destroyer of the idols on the outside but he succumbed to the idols within; who was anointed in his head (mind) to serve, but had a heart that was diametrically opposite to obeying the commandments of the Lord.

2 Kings 10:16-17; 28-31(KJV)
16 And he said, Come with me, and see my zeal for the LORD. So they made him ride in his chariot.
17 And when he came to Samaria, he slew all that remained unto Ahab in Samaria, till he had destroyed him, according to the saying of the LORD, which he spake to Elijah.
…
28 Thus Jehu destroyed Baal out of Israel.
29 Howbeit from the sins of Jeroboam the son of Nebat, who made Israel to sin, Jehu departed not from after them, to wit, the golden calves that were in Bethel, and that were in Dan.
30 And the LORD said unto Jehu, Because thou hast done well in executing that which is right in mine eyes, and hast done unto the house of Ahab according to all that was in mine heart, thy children of the fourth generation shall sit on the throne of Israel.
31 But Jehu took no heed to walk in the law of the LORD God of Israel with all his heart: for he departed not from the sins of Jeroboam, which made Israel to sin.

Hosea 1:4 (KJV)
4 And the LORD said unto him, Call his name Jezreel; for yet a little while, and I will avenge the blood of Jezreel upon the house of Jehu, and will cause to cease the kingdom of the house of Israel.