I will quote verses 4-5 & 15. They say this:
And he did that which was right in the sight of the LORD, according to all that his father Amaziah did. And he sought God in the days of Zechariah, who had understanding in the visions of God: and as long as he sought the LORD, God made him to prosper...And his name spread far abroad; for he was marvellously helped, till he was strong.
Here we have a young prince whose father had been murdered. He had been crowned King when he was barely old enough to drive. He sought God. He was teachable. He was the sovereign of the land, yet he allowed himself to be discipled by the prophet Zechariah. So far his legacy was pure gold, but (you'll see this if you read the entire chapter)when he was strong, he grew proud, to his destruction. Uzziah was no longer satisfied to be King only, he also wanted to burn incense on the altar of incense. That function was reserved for the priests, and when the righteous king of Israel rebelled in this fashion God struck him down with leprosy, by which he soon died.
The final verse of the chapter says this:
So Uzziah slept with his fathers, and they buried him with his fathers in the field of the burial which belonged to the kings; for they said, He is a leper: and Jotham his son reigned in his stead.
The turning point in this man’s life is recorded in verses 15-16, “…for he was marvelously helped, till he was strong. But when he was strong, his heart was lifted up to his destruction.” Three words: strong, pride, destruction. Now do not think that Uzziah just all the sudden fell off the righteousness log; he did not wake up one morning and say, “Today is good day to turn my back on God!” No, at various places along the line of this man’s life he began to make course corrections for the worse. At some point he began to be unteachable, forsaking the godly and wise instruction of Zechariah.
Uzziah, for whatever reason, had begun, not all at once but over the course of time, to stop following after God as he once had, and as a result he no longer did that which was right in the sight of the Lord. Somewhere in the secret place of Uzziah’s core he began to believe that he was the reason for his own success.
“From whence cometh my help,” asks the Psalmist, and in his past Uzziah would unequivocally answer, as the Psalmist did, “My help cometh from the LORD which made heaven and earth” (Psalm 121:1-2). But now Uzziah decided that he could do what he wanted and go where he pleased. No longer did Uzziah’s help come from the Lord; now he followed the Frank Sinatra theory. And the king would look out upon Jerusalem and say:
To think I did all that;
And may I say - not in a shy way,
No, oh no not me,
I did it my way.
How tragic would it be to live a life of usefulness, only to leave a legacy that spoke of failure? About Uzziah they said, "He is a leper."