John 8:49 - Albert Barnes' Notes on the Bible

I have not a devil - To the first part of the charge, that he was a Samaritan, he did not reply. To the other part he replied by saying that he honored his Father. He taught the doctrines that tended to exalt God. He taught that he was holy and true. He sought that men should love him and obey him. All his teaching proved this. An evil spirit would not do this, and this was sufficient proof that he was not influenced by such a spirit.