God sees everything we do.

But  the children of Israel committed a trespass regarding the accursed things, for Achan the son of Carmi, the son of Zabdi, the son of Zerah, of the tribe of Judah, took of the accursed things; so the anger of the Lord burned against the children of Israel. Now Joshua sent men from Jericho to Ai, which is beside Beth Aven, on the east side of Bethel, and spoke to them, saying, “Go up and spy out the country.” So the men went up and spied out Ai. And they returned to Joshua and said to him, “Do not let all the people go up, but let about two or three thousand men go up and attack Ai. Do not weary all the people there, for the people of Ai are few.” So about three thousand men went up there from the people, but they fled before the men of Ai. And the men of Ai struck down about thirty-six men, for they chased them from before the gate as far as Shebarim, and struck them down on the descent; therefore the hearts of the people melted and became like water.
Joshua 7:1-5 - NKJV