Hezekiah took Isaiah's sensible advice and then had a complete change in thought. He started to do good deeds, and the king of Israel was once more filled with the spirit of Yahweh and becoming a follower of the exemplar-king, David. Hezekiah abided by the word of the Lord by living through the Torah and obeying the preaching of Isaiah, the prophet of that time. He began to renew the worship of Yahweh after the long period of time in which people had worshipped false gods, idols, and ba"als. "He abolished the shrines and smashed the pillars and cut down the sacred post. He also broke into pieces the bronze serpent which Moses had made, for until that time the Israelites had been offering sacrifices to it "(2 Kings 18:4). Simultaneously, he brought about once again the important tradition of Passover. This was a great advancement religiously for the Judeans because it showed a renewal in obedience in God as well as in serving the people, which is the last requirement of a constitutional Judean king. 2 Chron 30:13,26 talks about how "a great crowd assembled at Jerusalem to keep the Feast of Unleavened Bread in the second month, a very great congregation. They set to and removed the altars that were in Jerusalem, and they removed all the incense stands and threw them into Wadi Kidron.There was great rejoicing in Jerusalem, for since the time of King Solomon son of David of Israel nothing like it had happened in Jerusalem." Serving God and the people by obeying God and the Torah is the best way to be a good ruler.
Ahaz, however, was a bad king. Firstly, Yahweh did not appoint him king; therefore he was not a charismatic leader. Being a charismatic leader means that one is filled with God's spirit, so they are like David: faithful and true to Yahweh. He also makes certain that his nation is a nation set apart from other nations and that his nation does not get embroiled in other nations" affairs.