The accuser of the brethren

“Then I heard a loud voice in heaven say: ‘Now have come the salvation and the power and the kingdom of our God, and the authority of His Christ. For the accuser of our brothers, who accuses them before our God day and night, has been hurled down.’” Revelation 12:10
In Revelation 12 we see the battle of the ages taking place between Michael, leading the godly angels, and Satan, leading the fallen angels. When Satan fell, he drew one third of the angels with him (Rev. 12:4). Then he made it his mission to attack Israel (depicted here as the woman), to prevent her from producing the Messiah.
During the Tribulation there will be yet another angelic battle (Rev. 12:7). At the end of it, Satan will be permanently barred from entering heaven. At present, although he does not dwell in heaven, he has access (see Job 1:6-7, Rev. 12:10). In today’s verse we read that at present he accuses us day and night before God. In fact, ‘accuser’ is what the name Satan means. He accuses us before God of our sin, and our failings. But praise God that we have an intercessor in the person of Jesus Christ – who, after Satan is done, simply says to the Father, ‘This one’s with Me.’ Our sin was already paid for at the cross. The accusations may be true, but the payment has already been made.
Satan also accused God before Eve in the Garden of Eden. He made out that God was unfair, that He was withholding something good from her (Gen. 3:5). He still does this today, particularly in the hearts of unbelievers. This is where the questions, ‘If God is good, why does [x] happen?’ come from. When it all boils down, this is accusing God of being unfair.
Accusing the brethren – believers – is the hallmark of Satan’s work. We need to be diligent not to accuse other people, otherwise we are actually doing the work of Satan. We must not criticise other believers or accuse them. God does not condemn them. And the reality is, we are just as guilty as they are – and our sins are covered by the blood of Christ, just as theirs are. God hears enough accusations about people from Satan. We don’t need to add to it!