2 Kings 8:27
And he walked in the way of the house of Ahab, and did evil in the sight of the Lord, as did the house of Ahab: for he was the son in law of the house of Ahab.
Cross-reference
In 2 Kings 17:19, Judah as a whole walked in Israel's customs, showing Ahaziah's personal sin reflected the nation's pattern.
In 2 Kings 21:3, Manasseh also followed Ahab's practices, showing a recurring pattern of kings imitating Ahab's idolatry.
In 2 Chronicles 22:3, Ahaziah's mother Athaliah is named as the counselor leading him to walk in Ahab's ways, specifying the source of influence.
In 2 Chronicles 22:4, his father's counselors after his death continued the evil counsel, showing multiple sources leading him astray.
In 1 Kings 22:52, the other Ahaziah (king of Israel) also did evil by walking in his parents' ways, paralleling Judah's Ahaziah.
In 2 Chronicles 18:1, Jehoshaphat's marriage alliance with Ahab set the stage for Ahaziah's own connection to the house of Ahab.