The devil means accuser.  Satan means adversary.  In the story of Job he tells God that He is not fair.  The adversary sets himself against us and is ever accusing us.  Persons who are constantly putting someone else down are doing Satan’s work.  Humans have enough trouble without us playing the devil in this way.  Satan condemns even the good.  The Spirit convicts us of Truth and says, “This is the way, walk in it” (Isa 30:21). -HLS

“Then I heard a loud voice in heaven, saying, ‘Now the salvation, and the power, and the kingdom of our God and the authority of His Christ have come, for the accuser of our brethren has been thrown down, he who accuses them before our God day and night.’” Revelation 12:10 (NASB)