What does Satan do when we sin?

Scripture identifies Satan as the accuser of the brethren, who accuses them before God day and night. Every time a believer sins, he is the first to run and tell God about it, constantly letting the Lord know where they have failed. He is ultimately cast down for this accusing work.

Les teaches that Revelation 12 shows Satan as the accuser of our brethren. After Michael and the holy angels fight and defeat him, he is cast out, and heaven announces salvation, strength, the kingdom of our God, and the power of His Christ. Les explains that Satan is the one accusing, and he accuses you and me. Every time we sin—and we all do—Satan is the first to run and tell God about it. He is constantly letting the Lord know where we have failed, accusing the brethren before God day and night.

Revelation 12:10

And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.

How does Satan accuse believers before God?

Satan accuses believers before God by constantly bringing their sins and failures to His attention day and night. As the accuser of the brethren, he points out every time they sin, running to tell God where they have failed, until he is cast down from his access to heaven.