Can Satan use good things, and how can you tell if it's the evil spirit speaking?

Les explains that Satan does not care what he uses, as long as he can keep people from the truth. He will use good things, and it can still be the evil spirit, rather than the Holy Spirit, that is speaking. In Galatians, the persuasion to go back under legalism did not come from the Holy Spirit who brought them out of paganism; it came from the same evil spirit that held them in paganism until the Gospel freed them. Satan never gives up. Les also notes that every believer faces a constant warfare between the new nature, which is Holy Spirit driven, and the old nature, which still has its roots in the Satanic powers of the curse. The spirit that takes believers back into a false gospel is not the same Spirit that brought them out; it is the opposite. Verse 8 says, “this persuasion cometh not of him that calleth you.” So the way to tell is whether the persuasion agrees with the Spirit who called them or pulls them back into legalism and a false gospel.