2 Kings 10:29

Jehu departed not. Jehu fought evil, but he employed evil to do it. Sin can never be overcome by sin. Wickedness in one form will never root out wickedness in other forms. Baal worship needed to be wiped out from Israel. But there was little of permanent good to be accomplished if Baal was not to be replaced by the worship of God. Jehu failed in that he did nothing to transform the hearts of his people. A man who himself did not depart from the sins of Jeroboam that had brought evil upon Israel, could hardly hope to deliver his nation from the sad effects of such iniquity.

The golden calves. These were the most important religious shrines in the nation, and were among the chief sources of the nation’s evil. By this time Bethel and Dan were no doubt regarded as national shrines, and held the same place in the regard of the people of Israel as did the Jerusalem Temple in Judah. If Jehu’s main aim had been righteousness and a return to Jehovah, he would have turned his zeal against the golden calves of Dan and Bethel as well as the house of Baal.