He who sins is of the devil, for the devil has been sinning from the beginning. To this end the Son of God was revealed, that he might destroy the works of the devil.
The devil sinneth from the beginning ...  This does not mean from the beginning of time, nor from the beginning of Satan's existence, nor from the beginning of the Christian age, but "from the beginning of human sin"[19] in the garden of Eden.  Jesus said of Satan, that "he was a murderer from the beginning" (John 8:44); and these texts shed a great deal of light on the purpose of the evil one.  By Christ's denomination of him as a murderer," the purpose of Satan to accomplish the death of Adam and Eve is evident; and from John's mention of the devil's sinning from that same time shows that Satan's deception of Eve was a diabolical and sinful act.  It was for that sin that God pronounced the curse upon Satan.