The Ven. Abp. Fulton Sheen revealed that owing to Satan's hatred for the Redemption wrought by the Cross of Christ, Satan also hates the voluntary crosses carried by Catholics that produce the fruit of redemptive suffering.
During a talk in the 1970s titled, "The Devil," Abp. Sheen explained, "The essence of the satanic or the diabolic is the hatred of the Cross of Christ. ... What is the satanic from the biblical point of view? It is the contempt of the Cross of Christ. It is anti-Cross."
The archbishop added, "The demonic very simply is the anti-Cross. The anti-disciplined life. The anti-Christ. That's the satanic."
One of the biblical examples Abp. Sheen used to make his point was from chapter 16 of Matthew's Gospel where Our Lord told the disciples he must suffer and die at the hands of the Jewish leaders. Matthew 16:22–23 reads, "Peter, taking Him aside, began to chide Him, saying, 'Far be it from Thee, O Lord; for this will never happen to Thee.' He turned and said to Peter, 'Get behind me, Satan.'"
The archbishop asks, "Why did Our Lord call him Satan? Why was Peter satanic?"
He answers, "The satanic is the contempt of the Cross, mortification and self-denial and therefore of Christ Himself." He further relates, "Notice how much we've given up — mortification, self-denial, discipline in schools ... The decline of the spirit of discipline is a hatred of the Cross."
This sheds light on why in chapter nine of Mark's Gospel, Our Lord affirmed that fasting was necessary to cast out certain demons. After failing to cast out the demon from a possessed boy, the disciples asked Christ privately why they weren't able to cast out the devil? In Mark 9:28, Our Lord responds, "This kind can be cast out in no way except by prayer and fasting."
Watch the panel discuss the Catholic-led war against the diabolic in The Download—Reality of Evil.