Josh 7:1-18
Then the People of Israel violated the holy curse. Achan son of Carmi, the son of Zabdi, the son of Zerah of the tribe of Judah, took some of the cursed things. GOD became angry with the People of Israel.
2 Joshua sent men from Jericho to Ai (The Ruin), which is near Beth Aven just east of Bethel. He instructed them, "Go up and spy out the land." The men went up and spied out Ai.
3 They returned to Joshua and reported, "Don't bother sending a lot of people — two or three thousand men are enough to defeat Ai. Don't wear out the whole army; there aren't that many people there."
4 So three thousand men went up — and then fled in defeat before the men of Ai! 5 The men of Ai killed thirty-six — chased them from the city gate as far as The Quarries, killing them at the descent. The heart of the people sank, all spirit knocked out of them.
6 Joshua ripped his clothes and fell on his face to the ground before the Chest of GOD, he and the leaders throwing dirt on their heads, prostrate until evening.
7 Joshua said, "Oh, oh, oh . . . Master, GOD. Why did you insist on bringing this people across the Jordan? To make us victims of the Amorites? To wipe us out? Why didn't we just settle down on the east side of the Jordan? 8 Oh, Master, what can I say after this, after Israel has been run off by its enemies? 9 When the Canaanites and all the others living here get wind of this, they'll gang up on us and make short work of us — and then how will you keep up your reputation?"
10 GOD said to Joshua, "Get up. Why are you groveling? 11 Israel has sinned: They've broken the covenant I commanded them; they've taken forbidden plunder — stolen and then covered up the theft, squirreling it away with their own stuff. 12 The People of Israel can no longer look their enemies in the eye — they themselves are plunder. I can't continue with you if you don't rid yourselves of the cursed things.
13 "So get started. Purify the people. Tell them: Get ready for tomorrow by purifying yourselves. For this is what GOD, the God of Israel, says: There are cursed things in the camp. You won't be able to face your enemies until you have gotten rid of these cursed things.
14 "First thing in the morning you will be called up by tribes. The tribe GOD names will come up clan by clan; the clan GOD names will come up family by family; and the family GOD names will come up man by man. 15 The person found with the cursed things will be burned, he and everything he has, because he broke GOD's covenant and did this despicable thing in Israel."
16 Joshua was up at the crack of dawn and called Israel up tribe by tribe. The tribe of Judah was singled out. 17 Then he called up the clans and singled out the Zerahites. He called up the Zerahite families and singled out the Zabdi family. 18 He called up the family members one by one and singled out Achan son of Carmi, the son of Zabdi, the son of Zerah of the tribe of Judah.

This is in the Bible to warn us of how much God sees everything that we do! Achan thought that no one saw him do this and they probably didn’t but God saw him and punished him. We are no different! God sees us too and if we look to other things instead of Him we will be punished too!