​A dirty hand can't do clean work.

Scripture:
"When they came to the threshing floor of Chidon, Uzza put out his hand to hold the ark, because the oxen nearly upset it. The anger of the Lord burned against Uzza, so He struck him down because he put out his hand to the ark; and he died there before God."
1 Chronicles 13:9-10 NASB

"[David] said to them, “You are the heads of the fathers’ households of the Levites; consecrate yourselves both you and your relatives, that you may bring up the ark of the Lord God of Israel to the place that I have prepared for it. Because you did not carry it at the first, the Lord our God made an outburst on us, for we did not seek Him according to the ordinance.”
1 Chronicles 15:12,13 NASB

Application:
In our eyes, it might seem harsh for God to kill Uzza, who tried to steady the ark when it appeared it would fall. But it's not our eyes that matters.
It's God's.
God will not accept the presence of sin, evil, or uncleanliness in His presence. (That's why even the Lord Jesus, dying on the Cross for us, was swept out of the righteousness of God and made a sacrifice: The Lamb of God had taken on on all the world's sin and had to be sacrificed. See Matthew 27:46) There are clues in later chapters that Uzza was not consecrated at the time he reached out his hand and dared to touch the Ark, filled with righteous items. David had a second chance. He reasoned, or was divinely told after asking (e.g., 1 Chronicles 14:10,14), that there was not the requisite sanctification in the prior attempt.
This is important. Our fine clothing, makeup, grooming, lineage, church contributions, or heritage don't make us righteous, and we can't "pretend" that we are clean when we go before God. We really have to be repentant and sincere.
So David sincerely repented and changed. He cleaned himself up, ordered sanctified Levites only as the carriers of the Ark, and proceeded appropriately. The result was success, and God helped them. (1Chronicles 15:26) We can't fool God, and we can't use human mental gymnastics to rationalize what we want to do in the flesh. It's not what we think is "good enough" that counts.
It's what God says is good.

Prayer:
Father, give us vision through Your eyes even when we think we are seeing what's right. Amen.