Not that hard at all, actually, He said the Paraclete would bring it to your understanding. Morality and ethics are its guidepoints, just as they instructed the hard of heart for centuries slavery was wrong and they resisted its instruction too.
If you can learn from his parables, you can take the lessons to many other evils in the world - unless your heart is rooted in the adversary that wants d*mn well to keep them unquestioned. Then you will simply retreat from its leadings in fear and say, "Go they way; when I have a convenient season I will call for thee" instead.