Consequence of unfaithful in regard to the devoted things

Joshua 7:1-20
But the Israelites were unfaithful in regard to the devoted things. They failed to attack Ai and they were routed by the men of Ai, who killed about thirty-six of them.
I will not be with you anymore unless you destroy whatever among you is devoted to destruction.
Early the next morning Joshua had Israel come forward by tribes, and Judah was chosen. Then clan, family be chosen, and Achan son of Karmi, was chosen.
Achan replied, “It is true! I have sinned against the Lord, the God of Israel."
Why?
Because Achan defied God's ban 36 men died at Ai, and the whole nation was shamed before their Canaanite enemies. The disobedience of one individuals of one individual touches the whole community: where wrong has been done there is corporate, as well as individual, accountability.
God is holy so if any sin exists among people, God will not with them.
God knows everything, Achan did not face his sin until the lot was chosen to him.
How?
Let me be holy, for God is holy. Obey his commands and fear his holy name.