
This is a strange chapter with a lot of things that we don't understand and that make us feel uncomfortable. This is a good reason why we can be sure that the bible is not man made. If this was a man made religion, the story about Uzzah would have been removed because it seems so unfair and doesn't make God look nice!
The story about Uzzah reminds me how holy God is. He is not a domesticated pet, he is perfect, holy and powerful and I am not. They should not have been transporting the ark on a cart and Uzzah should not have touched it. Sin lead to death. The amazing thing here is not that God killed Uzzah for his sin, but that I am still here. I have sinned against God today and he did not wipe me out. That's amazing. That's his love and mercy and if I forget the holiness and wrath of God towards sin, I can't understand His love.
On the second attempt to bring the ark back. David displays worship that apparently makes him look foolish. but he recognises who the worship is for... God (v21). He is more concerned with his attitude before God than what it looks like to other people. I need to let that challenge me. I want to worship God and look cool at the same time. Sometimes (not often!) that might happen, but I need to be solely concerned with the attitude of my heart in worship and obedience to God.