Jehu went beyond the call of duty in doing God's work.
2 Kings 9: 6 So Jehu got up and went inside; the young man poured the oil on his head, saying to him, "Thus says the Lord the God of Israel: I anoint you king over the people of the Lord, over Israel. 7 You shall strike down the house of your master Ahab, so that I may avenge on Jezebel the blood of my servants the prophets, and the blood of all the servants of the Lord. 8 For the whole house of Ahab shall perish; I will cut off from Ahab every male, bond or free, in Israel.
Jehu was asked to kill the entire family of Ahab. However he went beyond that and killed many other people who are associated with Ahab.
2 Kings 9:11 So Jehu killed all who were left of the house of Ahab in Jezreel, all his leaders, close friends, and priests, until he left him no survivor.
This action was later condemned by God and judgment pronounced on Jehu.
Hosea 1:4 And the Lord said to him, "Name him Jezreel; for in a little while I will punish the house of Jehu for the blood of Jezreel, and I will put an end to the kingdom of the house of Israel. 5 On that day I will break the bow of Israel in the valley of Jezreel."
It is possible in our zeal to do God's work to be "over-doing" leading to terrible consequences. For example, we are asked to share our faith with people and to do so with gentleness and respect but some people in their zealousness have resorted to condemning others for their false beliefs. That is going beyond the call of duty even if the ultimate intentions are right.
1 Pet 3:15 Instead, you must worship Christ as Lord of your life. And if you are asked about your Christian hope, always be ready to explain it. 16 But you must do this in a gentle and respectful way.
Denounced the sin of others while not aware of own sins.
He eliminated one form of idolatry, Baal worship, only to uphold another by continuing to worship the golden calves Jeroboam had set up.
Jesus warned us not to notice other people's fault while failing to recognize our own.
Matt 7:3 Why do you see the speck in your neighbor’s eye, but do not notice the log in your own eye?
Whenever we are tempted to criticize someone, use this as an opportunity to reflect on our own life. Are we guilty of the same kind of sins that person is? This is actually an excellent method to find out our own faults. We usually cannot detect our own faults and using other people's faults is a good way to find out our well hidden faults.
Jesus is very much against hypocrisy. He reserved the harshest words of contempt for the Pharisees. He had kinder words for prostitutes and tax collectors.
Was devoted to God only to the point that obedience served his own interests
"Why did Jehu destroy the idols of Baal but not the gold calves in Bethel and Dan? Jehu’s motives may have been more political than spiritual. (1) If Jehu had destroyed the gold calves, his people would have traveled to the Temple in Jerusalem, in the rival southern kingdom, and worshiped there (which is why Jeroboam set them up in the first place; see 1 Kings 12:25-33). (2) Baal worship was associated with the dynasty of Ahab, so it was politically advantageous to destroy Baal. The gold calves, on the other hand, had a longer history in the northern kingdom and were valued by all political factions." (Life Application Bible)
Are we devoted to God only if it served our own interests? Do we serve God only in ministries where we will be recognized by men? Do we serve God only because we want God's rewards and not because we truly love Him or His people? Are you willing to give money to the church without the expectation that you will get back monetary blessings from God?
Partial obedience can lead us to trouble
2 Kings 10: 28 Thus, Jehu destroyed every trace of Baal worship from Israel. 29He did not, however, destroy the gold calves at Bethel and Dan, the great sin that Jeroboam son of Nebat had led Israel to commit.
This disobedience caused him dearly.
2 Kings : 31But Jehu did not obey the law of the Lord, the God of Israel, with all his heart. He refused to turn from the sins of idolatry that Jeroboam had led Israel to commit. 32 At about that time the Lord began to reduce the size of Israel’s territory.
We must not think that we have done well simply by following some of God's laws. Any kind of sin can give Satan a foothold in our lives and cause damage to it. Jesus instructed us to strive for perfection, not partial obedience.
Matthew 5:28 But you are to be perfect, even as your Father in heaven is perfect.
In this life we cannot be flawless, but we can aspire to be as much like Christ as possible.