The failure to grasp the root of both good and evil (both of which are realities and not only principles) is paramount to the rising impotence of the church. When confronted with real evil, it is impossible to deny its' reality (i.e., the barbaric ISIS propaganda videos.) Without the true knowledge of good and evil, we are rudderless ships at the whim of changing cultural currents and tides. Good exists not only as a moral principle, but as an entity - i.e., God Himself who defines good by His very nature.
I increasingly believe the strongest philosophical argument for the existence of God is the moral argument. The moral argument begins with the fact that all people recognize some moral code (that some things are right, and some things are wrong). Every time we argue over right and wrong, we appeal to a higher law that we assume everyone is aware of, holds to, and is not free to arbitrarily change. Right and wrong imply a higher standard or law, and law requires a lawgiver. Because the Moral Law transcends humanity, this universal law requires a universal lawgiver. This, it is argued, is God. Without God there would be no objective basis for morality, no life, and no reason to live it. Yet all these things do exist, and so does God. Thus, the moral argument for the existence of God.
So too, does evil exist not only as a moral principle but as a specific entity. An Italian Bishop is speaking out after witnessing his first exorcism--an event he said would convince anyone of the existence of the devil. "All you have to do is witness an exorcism to understand that evil is a specific entity, as well as a reality," Archbishop Erio Castellucci told the Italian daily Il Resto del Carlino. The Archbishop says he'd seen possessed people but had never witnessed an exorcism. Then, in 2015 he was called by two priest exorcists in his archdiocese to be present during an exorcism for a man considered a "difficult case."
Archbishop Casellucii says when he walked into the parish church in Modena where exorcisms are performed, the demon-possessed man started to scream, "Get out, get out of here, you will have a bad death." After that he fell into a trance-like state.
"Then it seemed as if he had woken up and in an instant drove his fingernails into the back of my hands," Archbishop Castellucci continued. "He had a diabolical look on his face and he uttered unrepeatable insults and curses." The man "told me I would die in a traffic accident and while he was saying it he looked pleased." Archbishop Castellucci says he wasn't concerned about the curses. "My life is in the hands of the Lord Jesus and certainly not in that demon's. I wasn't worried at all. The word of God teaches that the curses are ineffective," he explained.
Following the exorcism, Archbishop Castellucci told reporters that discernment is important in cases of alleged possession, because many cases belong more to "the competence of a psychiatrist than an exorcist." He went on to stress the importance of prayers of deliverance to help bring healing (Mark 9:29).
Our understanding of good is directly proportional to our understanding of God. The better we know God through the revelation of Jesus Christ, the stronger our grasp of good becomes. Without the true knowledge of good and evil, we are Don Quixote flailing at windmills.