But Jehu took no heed to walk in the law of the LORD God of Israel with all his heart; for he did not depart from the sins of Jeroboam, who had made Israel sin. ~ 2 Kings 10:31
God Made Jehu king and used him to do to Ahab and his family God said would happen.
Jehu had good opportunity to walk with God and he eventually got rid of many idols, yet he compromised by leaving the ones which had originally turned people away from God.
Even when we do what God asks, and are used by God to accomplish great things, if we leave sin in our lives, it will draw us away from God and unable to fully obey.