As a friendly neighborhood angelologist, I periodically field calls about supernatural encounters. For example, a group of students recently approached me with some questions spurred on by their experiences on a disaster relief trip to North Carolina. While staying at a vacant building during the trip, some of the students had some uncanny, bizarre experiences. Was it demons? What could demons do anyway?

During such moments, when people are scared or confused or just plain weirded-out, folklore and superstition often step in and complicate matters all the more. Naturally, that leads to a confusion between biblical teaching and cultural narratives. The students and I were able to have a great conversation about spiritual warfare and how to assess these kinds of experiences. I hope it was helpful. But I’ve come to realize that the confusion between folk demonology and biblical teaching isn’t going away.

The topic of demonology is becoming more culturally significant as interest in the occult and paranormal continues to grow. “Spiritual” religions, such as Wicca, are some of the fastest growing in the Western world. In fact, the demand for exorcisms has risen so much that the Roman Catholic diocese of Lugano appointed an official exorcist in 2025. We must address renewed interest with renewed discernment.

In Satan Cast Out: A Study in Biblical Demonology, a 1975 book by the late Frederick Leahy, formerly principal of the Reformed Theological College in Belfast, he tackles two common problems in Christian demonology. First, he pushes back on the tendency to pagan beliefs about spiritual guide the interpretation of the Bible. Second, he resists attempts to frame the way Christians think about demonology through experience instead of Scripture. As interest in the supernatural grows, Leahy’s warnings seem timely and relevant.

Uniqueness of the Bible

Some popular books on angels, demons, and similar subjects delight in telling us what the biblical author must have thought in light of what other writers of his time period—well, at least of the ancient world—thought in their own religious contexts and in their own languages. The underlying notion is that the Hebrew prophets saw the world basically in the same way that the ancient near eastern world did. In contrast, Leahy notes, “The fact is that the Biblical doctrine of Satan and his demons is radically different from the views of gods and spirits prevailing in pagan cultures” (70).

The most glaring item left out in a comparative religions approach to demonology is the inspiration of the Holy Spirit. The largest distinguishing mark between the human author of Scripture and the writer of some pagan book of whatever antiquity and sophistication is that the Bible is God breathed (2 Tim. 3:16). Thus, Leahy argues, “To suggest that the Scriptures simply reflect common Jewish beliefs which in turn were largely moulded by pagan cultures is to deny the whole concept of Divine revelation” (70).

The authors of Scripture are God’s chosen writers. Their writing isn’t the interpretation of mere men of their times. It’s the word of God. That shapes the way we approach the Bible.

Between Doubt and Credulity

A second errant approach to demonology is to allow remarkable accounts to establish the framework by which we interpret Scripture. Some religiously minded people tend to be quite superstitious. Hence, they concede too much to showy antics and breathless anecdotes. Those who succumb to such things often lose sight of biblical standards.

According to Leahy, those who form their doctrine primarily on the basis of their experience “have allowed facts to determine their faith, instead of interpreting facts in light of their faith” (167). By “facts,” he means whatever a person claims to have seen without considering those events in light of Scripture. Though they may seem more immediate, contemporary experiences simply aren’t clearer than the content of Scripture.

Though they may seem more immediate, contemporary experiences simply aren’t clearer than the content of Scripture.

Of course, it’s not helpful to deal with strange experiences by denying they happened at all. That denial misunderstands the nature of humanity and all of creation as both spiritual and material. Many modern people, particularly theological liberals, argue that demons don’t exist and equate demonic accounts in Scripture to psychological disorders. For Leahy, that doesn’t sit right.

Instead, when dealing with someone who claims to be experiencing a demonic-possession, Leahy states that the counselor is “not called upon to diagnose or decide whether or not the person is demon-possessed, but simply to proclaim the liberating word of Christ and proclaim the name of Christ” (146). Any approach to understanding and dealing with spiritual beings, Leahy argues, “must be squarely based upon Biblical teaching, and must not be governed by any other considerations whatsoever” (164).

Contemporary Relevance

Many of the concerns Leahy raised half a century ago sound familiar to ongoing trends. For example, Leahy complains, “In some Christian circles there is an attitude to the name of Jesus which almost borders on magic” (164–65).

That superstition in the name of Jesus is demonstrated evangelical mystic John Eldredge when he tells readers to pray over hotel rooms to free them from the spiritual residue of the past occupants’ sin: “I cleanse this room now with the Blood of the Lord Jesus Christ—everything in the physical realm, everything in the spiritual realm.” We have a supernatural religion, but we do not have a superstitious one.

We have a supernatural religion, but we do not have a superstitious one.

Mirroring another contemporary trend, Leahy expresses concern about the rapid publication of books on spirits on demonology to meet growing demand:

In a day when we hear much about extrasensory perception, Ouija boards, black witches, exorcism and suchlike, there has been a tendency to rush out books on the occult, spirits, and demon-possession which pay scant attention to the Biblical evidence, pander to the sensational and often arrive at unwarranted conclusions. (8)

In contrast, he argues, “There is a crying need for an examination of this whole subject in light of Scripture alone, bearing in mind that the Scriptures are our only rule of faith and practice” (emphasis original, 8). This same need is present today.

Leahy’s method is well worth considering anew. And we’d also do well to heed his reminder that “the worship of the Triune God through the risen Christ, and the proclamation of Christ’s victory, are always infinitely stronger than all demonic forces in their strongest combinations” (172). Satan Cast Out is a biblically sound survey of demonology that can equip pastors and church leaders to deal with the rising tide of spiritualism and the occult.