Why did Uzzah have to die

I came across this familiar passage again this morning. In 2 Samuel 6, it is said that after David became King and had finally driven out the Jebusites who were the inhabitants in Jerusalem to turn it into the City of David (2 Samuel 5:6-7), he decided to bring back the Ark of the Covenant from the house of Abinadab. Uzzah was one of the sons of Abinadab. He and his brother Ahio were guiding the new cart which King David has made for the transport. However, the oxen that were pulling the cart stumbled and Uzzah reached out with his hand to take hold of the Ark. 2 Samuel 6:6-7 said that "the Lord's anger burned against Uzzah because of his irreverent act" and he struck him down and killed him. Because of this King David was angry - it is not clear whether he was angry with God or he was angry with Uzzah (for his irreverent act). But he was afraid of God and was not willing to move the ark to Jerusalem. He did eventually move the ark to Jerusalem after seeing how the ark blessed the household of Obed-Edom where he temporary placed the ark.

Whenever I read this passage my instinctive reaction is to judge God - he is vindictive, severe, and not nice at all. But this is so contrary to the rest of scripture so I must check my reaction and ask God to reveal the meaning of this passage even more sincerely. When I googled "Why did Uzzah have to die" there were quite a number of responses (57,400 search results in fact). I read through a number of them and summarized here:

Danny Bagget from the YouVersion (YouVersion is a new and popular free online bible translation) explained that in order to understand this, you have to make certain assumption. The ark had sat in the house of Abinidab for many years. We must assume that the event that took place on the threshing floor of Nakon was probably the consequence of years of Uzzah taking the ark of God in an irreverent manner. The ark in those days represented God's covenant love and his presence for the people of Israel ever since he took them out of Egypt, the land of bondage. The application for me is that I must not take God's love and his salvation flippantly. I should celebrate and honour his presence every day of my life.

Carey Scott did an extensive bible study on this passage in the simplebiblestudy.com site. His explanation is that Uzzah had the good intention to stop the ark from tumbling but nonetheless violated the strict instructions that God had given to the Israelites concerning the objects of the Tabernacle and the Ark of the Covenant. So the purpose of this story in the bible is to remind us (and to warn us) that we must not think that we can serve God but ignore his teaching. In Romans 15:4 and 1 Corinthians 10:11, it is clear that the stories in the old testament, as strange and sometimes incomprehensible as they can be, are recorded for our learning and admonition so that we may have hope and assurance for the future.