Joshua 7
v1-5: "It was only one person who sinned," and yet all of Israel committed the trespass. Achan by his sin "brought guilt on the whole community" of which he was part of. Our individual sin does not only affect us, it affect the local church we are a member of. Therefore, "we should watch over one another to prevent sin."
v6-9: "God knows what he is doing even though we do not. We may be sure that he has never done nor ever will do us any wrong."
v10-15: God "knows all the secret evil that goes on in the world, which is not generally known," and He could have told Joshua who had committed the sin that had caused Israel trouble, yet He doesn’t in order to "give the sinner an opportunity to repent and confess the sin."
v16-26: "Those who feel themselves under God’s displeasure and wrath should make sure they do not delay putting away their sin. Delays are dangerous, and there is no time to be idle." In Achan's refusal to confess his sin as he saw "the casting of lots pointing ever closer to him," we see how a heart is hardened by the deceitfulness of sin, "and it proved to be to his own destruction."