You Shall Not Murder

Response to comment [from an atheist]:  "I think a god that would smite Uzzah for steadying the ark of the covenant is immoral. If there is such a god it should be brought to trial, not worshiped."

This innate sense of right and wrong is the God-given conscience at work (Ro 2:5).  The judgment you would use against God, will be used against you (Job 8).

God is the giver of life.  He is the only one who may rightfully take life.

And they set the ark of God upon a new cart, and brought it out of the house of Abinadab that was in Gibeah: and Uzzah and Ahio, the sons of Abinadab, drave the new cart [2 Sam. 6:1–3].
"This is where David made his mistake. God had given specific instructions about moving the tabernacle and its furniture, but David did not follow those instructions. Someone might say, “Well, the Philistines didn’t either, and they got away with it.” They got away with it because they were ignorant. Light creates responsibility. If men have the light of the gospel, they are held responsible for rejecting it. I am not going to argue with you about the heathen in Africa, but I would like to argue with you about the heathen in my town and your town because they can hear the gospel, and their responsibility is great. If you turn your back on Jesus Christ, my friend, you can argue about the heathen all you want to, but you are lost and doomed and judged and are bound for eternal hell. That is the teaching of the Word of God. You may not like it; and, if you don’t, you ought to move out of this universe into another one. This is God’s universe and these are His rules.
So David goes to bring up the ark to Jerusalem, but he does it in the wrong way. The ark was constructed with rings on the four corners. Staves were put through those rings, and the ark was carried on the shoulders of the Levites. On the wilderness march the Kohathites put that ark on their shoulders and carried it. David simply did not follow God’s instructions.
Friend, in just such a way God wants the gospel to go out today. I sometimes wonder why He doesn’t get a better instrument than I am and why He doesn’t write the gospel in the skies. But Jesus Christ has to be carried through this world on the shoulders of those who are His own. That is God’s way of doing it today. That was God’s way of doing it in David’s day. David was wrong, so wrong. He is going to get into trouble, just as God’s people today get in trouble when they do wrong.."
McGee, J. V. (1997, c1981). Thru the Bible commentary. Based on the Thru the Bible radio program. (electronic ed.) (2:199-200). Nashville: Thomas Nelson.

See:

God and the Death Penalty by Bob Enyart

You Shall Not Murder