For statements like, "do unto others as you would have them do unto you," sure. Lewis' point is that he made all kinds of other claims that are either true or false. And if they are false, they are false in a way that led to lots of people dying for no reason. So Jesus was either saying those things that led to all his followers being killed either because he was crazy and believed what he said, because he was a liar and evil, or because he was telling the truth and good.