The "father of lies," Satan himself, employs deceit to lead men and women astray (John 8:44). With the same subtlety he used with Adam and Eve, the devil rarely attacks the goodness of God directly; rather, he uses trickery to get us to try and doubt the Lord (Gen. 3). Often he comes to us under the guise of what seems to be good and right, for as the Apostle Paul tells us in 2 Corinthians 11:14, "Satan disguises himself as an angel of light."
Such a battle plan is diabolically clever. Were the devil to come after us directly as a blatant promoter of wickedness, he would be easier to identify and resist. But since he so often attacks us under the guise of what is apparently good, we can find it difficult to see him sowing discord and causing a host of other problems before he has wreaked much damage on us and the church. Thus, let us take care to define what is good only by the Word of God, for Scripture is the only infallible guide to the Lord's standards.
We see in the Bible that Satan comes after believers with temptation and accusation. His work of temptation is somewhat easier to identify than his work of accusation. Sometimes he comes out and presents to us temptations regarding things that we know are evil. However, his work of accusation is almost always carried out under his disguising himself as an angel of light. Consider the patriarch Job. Satan accused Job of acting righteously only to secure the Lord's blessing (Job 1:6–11). In that case, the devil was speaking to God, but he does a similar thing in speaking to us and reminding us of our sin and getting us to doubt whether we truly have been forgiven. We say he acts as an angel of light at such times, for this accusation is hard to distinguish from the Holy Spirit's convicting us of sin and the degree of our sin against our holy Creator. But the Holy Spirit's conviction is always designed to restore our disrupted fellowship with our Father. The Spirit wounds so that He may heal (Ps. 147:1–3). Satan's accusations lead to despair or make us think that we can atone for our sins ourselves. When we see such things happening in our lives, we must preach the gospel to ourselves. Yes, our sin is deeply offensive to God, and we are to strive to put it to death. But there is no condemnation for those who are in Christ Jesus (Rom. 8:1). God really does forgive everyone who is in Christ by faith alone. When we remember this, we will gratefully serve Him in holiness.
The good news of the gospel is that God does not lay our sins to our account when we trust only in Christ for salvation. That doesn't mean our sin cannot disrupt fellowship with our Creator. It does mean that if we have sinned, we need not fear to ask His pardon. He will forgive us, and if we are in Christ, we can be sure that He will keep us safe before Him forever.