Be sober, be watchful! For your adversary the Devil, as a roaring lion, goes about seeking someone to devour. Resist him, steadfast in faith…1 Peter 5:8-9

Throughout the history of the Church, countless saints have written about the existence of the devil and the need for constant vigilance on our part. A popular trend today however is to portray the spiritual realm as a fantasy. Cardinal Robert Sarah has spoken on this dangerous trend. In his book, God or Nothing he writes, “Satan has even become a sort of purely fictional character. Hence the devil rejoices, because his acts are forgotten and hidden.”

Thankfully, there are many excellent resources out there that explain the nature of the spiritual battle in which we are engaged. One is Paul Thigpen’s Manual for Spiritual Warfare. I’ve selected a few excerpts from this work.

Like it or not, you are at war.

No matter who you are, whether or not you know it, you have a mortal enemy who wants to destroy you, not just in this life, but in the next.

No matter where you live on this planet, whether or not you can see it, you live on a hotly contested battlefield, and you can’t escape the conflict.

It’s a spiritual war with crucial consequences in your everyday life. And the outcome of that war will determine your eternal destiny.

The first rule of any type of warfare is to know your enemy. How can you fight an adversary you can’t identify? Worse yet, how can you avoid being a casualty in a battle going on all around you if you don’t even recognize that you’re in danger?

Your adversary is the Devil, with his army of demons. Your battle with him rages not only all around you, but also within you, a fierce conflict for control of your mind, your heart, and your ultimate destiny.

The world may scoff and tell you there is no Devil and no battle. But the world has been blinded to these realities by the Enemy himself. Its skepticism is part of his stealth strategy: Those who deny his existence are an easy prey.

Evidence of the battle

How do we know that demons are real? Consider first the accumulated evidence of confirming testimony. Throughout all history, peoples of vastly different cultures around the globe have affirmed the reality of the evil spirits, even when they have disagreed about most other spiritual realities. Many of our contemporaries as well, who by any reasonable standard are intelligent and in their right mind, have testified to having encounters with demonic powers.


The Exorcist, 1973

No doubt, some types of mental and physical illness have been wrongly attributed to demons, today as in the past. Nor can we deny that superstitions and legends about evil spirits abound. But these misguided ideas about the Devil don’t in themselves prove that he doesn’t exist, just as age-old beliefs about a flat earth don’t prove that our planet doesn’t exist.

Skeptics may demand “scientific” evidence. But what kind of relevant evidence would scientists be capable of measuring? The natural sciences measure time, matter, energy, and motion; the social sciences analyze human behavior. Demons have no physical bodies, and they aren’t human. We can’t put them in test tubes or subject them to psychoanalysis.

The most, then, that scientists can do is to observe the effects of demons on the physical world or on human behavior. But the prevailing mentality among scientists will press them to seek other explanations for such phenomena, even when these explanations are utterly inadequate.

In any case, for Catholics and other Christians the issue should be settled. A number of passages in the Bible testify to the existence of the Devil and his evil allies. The Gospel accounts in particular record that Jesus Christ Himself conversed with Satan. Our Lord’s debate with the Devil in the wilderness was not simply some inner dialogue with Himself about temptation.

Christ referred to demons on more than one occasion, and casting evil spirits out of those who were possessed was a striking and indispensible aspect of His mission. Of course, some interpreters have claimed that when Christ cast out evil spirits, He was simply healing a physical or mental disorder misunderstood as demonic possession. But we need only reply that on at least one occasion, at Christ’s command, the demons left their human host to take possession of animals instead.

You can’t cast a medical disorder out of a man into a pig. If Christ knew what He was doing, as Christians must insist, and if the Gospel account is historically reliable, as Christians must also insist, then we must conclude that the forces described there as evil spirits are precisely that.

The reality of demonic powers has been a constant doctrine of the Catholic Church ever since it was founded by Christ through His apostles. They and their successors spoke and wrote about Satan repeatedly. Though the centuries, the great teachers of the Church have consistently affirmed that he is real.

Satan’s existence has also been affirmed in authoritative declarations by Popes and Church councils. He’s referred to in the liturgy of the Church. And throughout the centuries, numerous saints, whose moral integrity and mental health could hardly be debated, have testified to personal battles with demonic assailants.

Yet even aside from the Churches teaching, the evidence of demonic intervention in human affairs is all around us daily. As Fr. Ronald Knox once wryly noted, “It is stupid of modern civilization to have given up believing in the Devil, when he is the only explanation of it.”

~Paul Thigpen, Manual for Spiritual Warfare, Tan-books.