All hidden sin will be revealed. We cannot keep sin hidden from God.

There was Achan, standing among the people, listening to Joshua say that there are devoted things in the camp that need to be removed. Achan doesn’t come forward and confess his sins in response. He doesn’t say It was me, forgive me, Lord. No, he stays hidden in the crowd. The next day the people are gathered before Joshua and the lot falls on the tribe of Judah. There are lots of clans in Judah, no need to panic, he says to himself. Then the lot falls on the clan of the Zerahites. No problem, there are still many households where I can hide. But then the household of Zabdi is taken, and now Achan must join the line of men as they walk towards Joshua. Finally it’s his turn and he is discovered.

Achan was unable to hide his sin from God, and that should be a lesson to us that all private sin will be uncovered. In the words of Jesus (Luke 12:2–3): Nothing is covered up that will not be revealed, or hidden that will not be known. God already knows about all our hidden sin.

There is nothing we can keep hidden from him and one day all our sins will be revealed. In the long run there is no such thing as private sin. Now this is not a truth to make us depressed or frightened, because if you believe in Jesus Christ then God has already paid the penalty for all your sins including those of which you are most ashamed. We follow a better Joshua, who in response to faith says, Your sins are forgiven (see Mark 2:1–12).