About Clement Harrold

October 2, 2025

In Mark 9, we hear about a man unaffiliated with the disciples who casts out demons in Jesus’s name:

John said to him, “Teacher, we saw a man casting out demons in your name, and we forbade him, because he was not following us.” But Jesus said, “Do not forbid him; for no one who does a mighty work in my name will be able soon after to speak evil of me. For he that is not against us is for us. For truly, I say to you, whoever gives you a cup of water to drink because you bear the name of Christ, will by no means lose his reward.” (Mark 9:38-40)

This same episode is also recorded in Luke 9:49-50, while St. Matthew’s Gospel includes a variation on the warning Jesus delivers to His disciples: “He who is not with me is against me, and he who does not gather with me scatters” (Matt 12:30).

For Catholic readers of the Gospels, the exorcist passage raises some interesting questions. Is Jesus saying that obedience to the apostles and their successors is unimportant? Is He implying that all branches of Christianity are equally valid? And if not, then what exactly is He trying to teach us in this passage?

The Necessity of Following Jesus

Before answering these questions directly, it is worth looking at a passage from the Old Testament which the Church Fathers saw as directly paralleling the version of the exorcist episode found in Luke 9. In Numbers 11, Moses appoints seventy men as elders of the people. Moses then stations these men around the tabernacle tent, whereupon the spirit of the Lord descends and bestows on them the gift of prophecy. Controversy arises, however, when it is discovered that two of the elders never came to the tent; they chose instead to remain in the camp. But in spite of this, the spirit of the Lord still descended upon them.

Upon realizing what has taken place, the Israelite commander Joshua is indignant: “My lord Moses, forbid them” (Num 11:28). Yet Moses refuses to do so, pointing instead to the evident holiness of the two elders in question: “Are you jealous for my sake? Would that all the Lord’s people were prophets, that the Lord would put his spirit upon them!” (Num 11:29).

What’s interesting about this whole exchange is that Moses defends the two maverick elders without condoning their failure to join the others at the tent. Something very similar seems to be going on in our Gospel passage involving the “rogue” exorcist.

At no point in the Gospel accounts does Jesus state or even imply that following Him is unnecessary or unimportant. On the contrary, in Luke’s ordering of events the exorcist episode is almost immediately followed by Jesus telling people from various walks of life that they must leave everything behind and follow Him (see Luke 9:57-62).

This literary context should help us to see that the evangelists do not celebrate the exorcist’s failure to follow Jesus, any more than they celebrate the failure of figures like Nicodemus or Joseph of Arimathea to openly follow Jesus. Clearly, following Jesus is still crucially important.

God Still Works Through Other Christians

As Catholic Christians, we know that the fullest expression of following Jesus is found in the Catholic Church which He founded. Indeed, no human being can be saved without the help of the Catholic Church, and God is continuously calling all people into that same Church. At the same time, we recognize as Catholics that God can and does bestow grace on baptized Christians of all denominations, just as the rogue exorcist could still cast out demons in Jesus’s name.

The Second Vatican Council’s dogmatic constitution Lumen Gentium reminds us that “many elements of sanctification and of truth” (8 §2) exist outside the visible confines of the Catholic Church. While the Catholic Church remains both the source and the goal of these elements, still she has never claimed a monopoly on exorcisms or other miracles, for the simple reason that God is not restricted in the ways that He bestows grace.

With that being said, there certainly are better and worse “methods” for obtaining grace. A holy Protestant might be able to cast out a demon, and we should give glory to God whenever that occurs. But this doesn’t change the fact that the most powerful spiritual weapons for casting out demons are found within the Catholic Church. Nor does it give Christians permission to adopt an “anything goes” to the faith, or to start claiming that all Christian denominations are equally valid.

Merely because a Christian is driving out demons in Jesus’s name, that doesn’t give their faulty theology a free pass (see Gal 1:9). In the Gospel texts, it is specifically the exorcist’s miracle-working—not his preaching—which Jesus defends. Hence in cases where we see Christians having success against the demons while also preaching false doctrine, the Catholic response should be to praise the holy works of such individuals, while at the same pointing out the flaws in their theology and inviting them to join the Catholic Church.

The Necessity of the Church

As Catholics, we also take seriously what Our Lord tells us about fraudulent prophets and miracle-workers:

Not every one who says to me, “Lord, Lord,” shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven. On that day many will say to me, “Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?” And then will I declare to them, “I never knew you; depart from me, you evildoers.” (Matt 7:21-23)

Jesus warns us that there will be those who claim to work miracles in His name, when in fact they are acting contrary to His purposes.

We see an example of this in the Acts of the Apostles, when a group of itinerant Jewish exorcists try to use the name of the Lord Jesus to cast a demon out of a man. The demon is unimpressed, and offers this scathing reply: “Jesus I know, and Paul I know; but who are you?” (Acts 19:15). The demon-possessed man then proceeds to assault all seven of the exorcists and send them flying out of the house.

This episode highlights the need for discernment. It also reminds us of the importance of the Catholic Church as God’s chosen “pillar and bulwark of the truth” (1 Tim 3:15). Although the Church did not exist at the time when the rogue exorcist was casting out demons, it does exist now. As such, all Christians should seek to conform themselves to the one, true, Catholic, and apostolic Church founded by Jesus Christ.

In a sermon on the passage from Mark 9, St. John Henry Newman pointed out while the exorcist cast out demons in Jesus’s name, today it is the Church which speaks in His name:

. . . ever since His resurrection that Church has existed, and has borne His Name; and to use His Name except in and under the Church, is to treat His sacred Name irreverently, which whoso does, God will not hold him guiltless, unless he does it in ignorance; and then, though his work will perish, he will be saved, yet so as by fire. (Sermon 14, “The Fellowship of the Apostles”)

Earlier in the same sermon, Newman compares the rogue exorcist with the New Testament figure of Apollos. The Acts of the Apostles describes Apollos as “an eloquent man, well versed in the scriptures” and one who was “instructed in the way of the Lord; and being fervent in spirit, he spoke and taught accurately the things concerning Jesus, though he knew only the baptism of John” (Acts 18:24,25).

Clearly, God was working through Apollos in wonderful ways. And yet, following the establishment of the Church, the baptism of John was no longer sufficient. It was for this reason that two Christian evangelists, Priscilla and Aquila, “took [Apollos] and expounded to him the way of God more accurately” (Acts 18:26). We see here that after the Church had been established, it became necessary for Apollos to submit himself to her authority.

Something very similar happens at the beginning of Acts 19, when St. Paul encounters a group of disciples who had only received the baptism of John the Baptist. Paul’s response is to immediately have them baptized in the name of the Lord Jesus (see Acts 19:1-7). This fits with what the Acts of the Apostles tells us more generally about the importance of being joined to Jesus and His Church through the sacrament of baptism (see Acts 2:40-42; 10:44-48; 11:15-18).

Since St. Luke is the author of Acts, these passages also shed light on the Gospel episode involving the rogue exorcist. Based on the witness of the New Testament as a whole, it is reasonable to infer that, like Apollos and the other disciples of John the Baptist, this exorcist would have been required to submit himself to the sacraments and authority of the Church just as soon as he became aware that the Church had been established.

A Call to Humility

St. Augustine helpfully summarizes the strands of our discussion when he says that what the disciples ought to have criticized in the exorcist was not his casting out demons in Jesus’s name, but rather his failure to join their company:

For what they ought to have forbidden was what was outside their fellowship, so that they might bring him over to the unity of the Church, and not a thing like this, in which he was at one with them, that is to say, so far as he commended the name of their Master and Lord in the casting out of devils. And this is the principle on which the Catholic Church acts, not condemning common sacraments among heretics; for in these they are with us, and they are not against us. But she condemns and forbids division and separation, or any sentiment adverse to peace and truth. For therein they are against us, just because they are not with us in that, and because, not gathering with us, they are consequently scattering. (Harmony of the Gospels, 4.5)

St. John Henry Newman argued along similar lines when he expressed his admiration for Protestant missionaries evangelizing in far-flung parts of the world. Although these missionaries “do not hold the whole truth of the Gospel,” nevertheless “we are not to behave towards them in a hostile way; rather we ought to bless God for whatever they mean well in doing, and pray Him that they may mean and act still better.”

Newman wrote those words when he was still an Anglican. In time, his prayer for Christians to “mean and act still better” would be dramatically realized in his own life when he took the step of joining the Catholic Church at great personal cost to himself. Perhaps this example of sincerity and humility can prompt us to draw one final lesson from the Gospel passage that we’ve been discussing here.

A striking element in Luke’s version of the passage is his emphasis on the fact that just because we say we follow Jesus, that doesn’t automatically make us holier than everybody around us, nor does it guarantee that the gifts of the Holy Spirit will be operative in us. In fact, only a few verses earlier in Luke 9 we hear about a father who “begged” the disciples to cast a demon out of his son, and yet they were powerless to do so (see Luke 9:37-43; cf. 9:1-2).

This should teach us that it’s one thing to be a member of the Catholic Church, but it’s another thing to actually take advantage of all the gifts and graces which come with being Catholic. It’s a reminder, too, that these gifts and graces are not magically activated in our souls simply because we attend Mass every Sunday or follow the Church’s teachings.

While it’s undoubtedly true that everyone ought to join the Catholic Church, simply being a member of the Church is not enough. A God-fearing and sincerely mistaken Protestant might be much closer to the Kingdom than an apathetic and hypocritical Catholic. What the Church needs—and what the world needs—is humble and zealous Catholics who are fully committed to following Jesus, and to living out the Gospel in His name.

Further Reading

St. Augustine, Harmony of the Gospels, 4.5-6

St. Cyril of Alexandria, Commentary on Luke, Homily 55

St. John Henry Newman, “Sermon 14. The Fellowship of the Apostles”

https://www.catholic.com/magazine/online-edition/does-being-catholic-matter

About Clement Harrold

Clement Harrold earned his master’s degree in theology from the University of Notre Dame in 2024, and his bachelor’s from Franciscan University of Steubenville in 2021. His writings have appeared in First Things, Church Life Journal, Crisis Magazine, and the Washington Examiner.