When Satan launches what Edwards calls “vexatious accusations of conscience” against believers, he is playing upon the believer’s resensitized conscience (awakened by the Spirit) while muting the believer’s full and free forgiveness (won by the Son). The way to combat these accusations from hell is therefore not to deny the first, but to remember the second. We should not downplay the reasonableness of our condemnation. We do deserve to be condemned. But another reality transcends our condemnation: the atoning work of Christ. This work not only frees us from accusation (negatively) but also renders us righteous (positively).
The gospel has defanged Satan. His bite is all gums and no teeth. When Satan accuses believers covered by the blood of Christ, he is (to switch metaphors) firing empty cartridges – his gun makes a bang, but it can’t ultimately hurt us. “Satan cannot hurt” true believers, Edwards preached. “All the powers of darkness, with all their spite and malice, can do them no harm, and the flames of hell cannot reach them.”
Dane Ortlund, Edwards on the Christian Life (pg. 151).