Reading through the books of the kings (1 Samuel – 2 Chronicles) can get confusing from time to time, trying to keep up with the different names and which king is ruling over which kingdom and so on (at one point a guy named Jehoram was reigning over Judah while another guy named Jehoram was reigning over Israel – see 2 Kings 1:17; 2 Kings 8:16), but if you can do your best to keep all that straight, it really is some enjoyable reading.
Let me briefly summarize what we find in 2 Kings 9-10 regarding the life and reign of Jehu as king over Israel, then make a couple quick observations.
In 2 Kings 9:1-13 Elisha sends one of the children of the prophets to Ramoth-gilead to anoint Jehu as king over Israel. The young man does so and prophecies that Jehu would smite the house of Ahab, thus avenging the blood of the prophets and servants of God that Jezebel had slain.
2 Kings 9:14-37 records how Jehu carried out God's death sentence on Joram, king of Israel, and his cousin (1 Kings 16:28; 2 Kings 8:16; 2 Kings 8:26) Ahaziah, king of Judah, as well as Ahab's infamous wife Jezebel, in Jezreel.
In 2 Kings 10:1-14, Jehu continues his campaign, killing the 70 sons of Ahab and 42 brethren of Ahaziah. 2 Kings 10:28 wraps up and summarizes the next section (described in Jehu Part 1), Thus Jehu destroyed Baal out of Israel.
If only the account ended there. But it doesn't. The rest of Jehu's life is wrapped up in these 3 sad verses.
2 Kings 10:29-31 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. 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. 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.
Jehu demonstrated zeal (2 Kings 10:16) and obedience in completing a task that God had given him to do, and God blessed him for it. Three of his sons sat on the throne as king of Israel.
But he sold himself short on God's blessings by only partially devoting himself to the word of God. Jehoahaz, Jehoash, and Jereboam all followed in the false worship of their father, and the entire nation suffered for it. How things could've turned out differently for Jehu and for the nation had he gone after God's will with all his heart.
Recently, I picked up a little book I've read a couple times through in the past entitled Absolute Surrender by Andrew Murray. Every Christian ought to read that book. God deserves nothing less from each of us. And if God tells the truth, then our lives and the lives of those around us will only be better for it.