2 Chronicles 20-21
Thus Hezekiah did throughout all Judah, and he did what was good and right and true before the Lord his God. And in every work that he began in the service of the house of God, in the law and in the commandment, to seek his God, he did it with all his heart. So he prospered.
King Hezekiah could have followed the easy path which the other kings and leaders chose. He could have face opposition and just decided to do what was easy. He was a good leader because he didn't seek selfish gain or fame. He initiated reforms that were necessary for the people, because God wanted them to happen. It is difficult to be led by values and convictions in a world that has very different ones.
The key to Hezekiah's strength to carry out some difficult reforms was that he wanted to please God and not men. Sought God with all his heart. Imagine what a leader could do if he/she sought after God with such abandon that nothing else mattered. To do so and maintain one's work ethic is important. So many people use their faith as an excuse not to work and do what is right. I have seen many religious people fail to have the personal discipline and values that are needed to do great things over the course of many years.
According to John Maxwell, Hezekiah led a lifestyle that was different from the other kings. He stepped out in faith to do what was right. He had a strong faith in God. He didn't give in to the criticism of an older generation who didn't like his reforms. He gave up personal time, energy and money. He had the daily discipline necessary to carry out his work for the long haul.