By Clement Harrold

January 1, 2026

Since angels and demons are pure spirits, they cannot experience physical harm. This means that angels and demons do not fight one another in the way that material creatures do. Instead, their combat takes a different form.

A War in Heaven

At the beginning of creation, all of the angels were united in serving God. But a time came when Lucifer, the most senior of all the angels, grew resentful towards God. Catholic tradition holds that this resentment arose when Lucifer realized God’s plan for humanity and the role which human beings, and in particular Our Lady, were destined to play as the crowning glory of all creation.

Rather than serve a peasant girl from Nazareth, Lucifer chose instead to rebel against his Creator. In the Old Testament, we find several texts which are interpreted by the Church Fathers as describing, in mystical terms, the pride and subsequent fall of Lucifer (see Isa 14:12-15; Ezek 28:12-17). In the New Testament, the book of Revelation implies that a full third of the angels joined Lucifer in his revolt, which caused a civil war in heaven:

And another portent appeared in heaven; behold, a great red dragon, with seven heads and ten horns, and seven diadems upon his heads. His tail swept down a third of the stars of heaven, and cast them to the earth. . . . Now war arose in heaven, Michael and his angels fighting against the dragon; and the dragon and his angels fought, but they were defeated and there was no longer any place for them in heaven. And the great dragon was thrown down, that ancient serpent, who is called the Devil and Satan, the deceiver of the whole world—he was thrown down to the earth, and his angels were thrown down with him. (Rev 12:3-4,7-9)

Here we see the dragon, who represents Lucifer, being defeated by St. Michael and his angels.

But how could such a battle ever take place between spiritual creatures who are incapable of physically harming or killing one another? The exorcist Fr. José Antonio Fortea offers some helpful insights on this question:

How can purely spiritual beings fight among themselves? What weapons do they use? Angels are spirits, so their battles must be purely intellectual. The only weapons that they can use are intellectual arguments. The angels gave reasons to the rebels for why they should return to obedience to God. The rebel angels countered with their reasons to support their position and spread their rebellion among the faithful angels. In this epic angelic battle, some who were inclined to rebel returned to obedience, while some of the faithful angels were seduced by the evil arguments of the rebels.

But not all [rebellious angels] suffer the same pains. Some angels were deformed more than others in the battle. Those who were more deformed suffer more; the least deformed suffer less. The intellects of the rebellious angels were deformed and darkened by the very reasons they used to justify the rebellion of their wills against God.

This helps us to see that the primordial battle between the fallen angels led by Lucifer—also known as Satan, meaning “adversary” or “accuser”—and the holy angels led by St. Michael was a battle involving intellect and spirit, rather than flesh and blood.

Angelic Combat

Since angels are pure spirits, their wills are now fixed either on serving God or hating him; there is no prospect of a holy angel now betraying God, or of a fallen angel now repenting of his evil ways. But does this mean that the holy and fallen angels no longer have anything to fight about?

Not so fast! While the realities of spiritual warfare are mysterious and complex, Sacred Scripture strongly suggests that the holy angels and the fallen angels (or demons, as they are popularly known) continue to engage in various forms of combat. An example of this comes in Jude 9, which recalls a Jewish tradition about the archangel Michael “contending” with the devil in a dispute over the body of Moses. Interestingly, Michael’s weapon of choice on this occasion is a simple prayer: “The Lord rebuke you.”

Another Scriptural example of what appears to be an angelic battle is found in Daniel 10:13: “The prince of the kingdom of Persia withstood me twenty-one days; but Michael, one of the chief princes, came to help me, so I left him there with the prince of the kingdom of Persia.” The narrator in this verse is an angel, who is explaining to Daniel how he was resisted for twenty-one days by the prince of the kingdom of Persia.

A number of the Church Fathers identify this prince as a demon, which fits with St. Paul’s description of the demons as “the rulers of this age” (1 Cor 2:8). In this instance, it seems that a demon was assigned by Satan to the kingdom of Persia to oversee its spiritual destruction. What is more, this demon appears to have been more powerful than the angel who appeared to Daniel; so much so that the angel was forced to appeal to St. Michael for assistance.

As already mentioned, it is important that we admit a certain degree of mystery in our interpretation of these biblical texts. On this side of the veil, we don’t fully comprehend the ways in which non-corporeal beings like angels and demons fight one another. But that doesn’t mean that spiritual warfare is nothing but mystery!

On the contrary, there is still plenty we can say about the ways in which the angels and demons fight one another. This is particularly true insofar as their spiritual combat relates to our own salvation. For although the angels and demons are no longer engaged in a battle over their own eternal fates, they are still very much engaged in the age-long war over the eternal fate of all mankind.

The Battle for Souls

Catholic tradition holds that all of the angels were created to serve as stewards over, and ministers to, the created world. As such, both angels and demons maintain a certain influence over material reality.

While the angels and demons do not have direct access to man’s higher powers of intellect or will, they are able to help or hinder us in our lower powers: in our bodies, our imagination, and our memory. The English theologian Fr. John Saward explains:

[A]ngels, holy or fallen, working outside the human will, can change it by persuasion, that is, by showing us some created good in its lovableness and attractiveness. So, for example, a man’s guardian angel might stir up a memory of his mother to deter him from an act that would scandalize her. Angels, holy or fallen, can cause changes in the will by stirring up the passions: pity for the poor man on the Jericho road moves the Samaritan to the act of charity. Even so, there is nothing deterministic about the angelic arousal of our feelings; we have the power to resist. (World Invisible: The Catholic Doctrine of the Angels, p. 103)

By influencing our lower powers, the angels and demons use their phenomenal intelligence to guide our intellects, persuade our wills, and shape our imaginations. The angels do this to help us on the path to salvation; the demons do it to drag us down to hell.

St. Thomas Aquinas, whom the Church celebrates as the Angelic Doctor, speaks beautifully about the role which the good angels play in guiding us on the path to heaven:

It is moreover manifest that as regards things to be done human knowledge and affection can vary and fail from good in many ways; and so it was necessary that angels should be deputed for the guardianship of men, in order to regulate them and move them to good. (ST I.113.1)

Following Our Lord’s words in Matthew 18:10, St. Thomas extends this logic to show how each of us is given a guardian angel to protect us throughout our life:

Man while in this state of life, is, as it were, on a road by which he should journey towards heaven. On this road man is threatened by many dangers both from within and from without, according to Psalm 141:4: “In this way wherein I walked, they have hidden a snare for me.” And therefore as guardians are appointed for men who have to pass by an unsafe road, so an angel guardian is assigned to each man as long as he is a wayfarer. (ST I.113.4)

Catholic doctrine holds that all of us receive the constant protection of our own guardian angel, as well as the aid of all the heavenly hosts whenever we call upon them:

For he will give his angels charge of you

    to guard you in all your ways.

On their hands they will bear you up,

    lest you dash your foot against a stone.

You will tread on the lion and the adder,

    the young lion and the serpent you will trample under foot. (Psa 91:11-13)

In the Old Testament, the prophet Elisha received a dramatic demonstration of angelic might, in an experience which the Church has long interpreted as depicting an enormous spiritual battle:

When the servant of the man of God rose early in the morning and went out, behold, an army with horses and chariots was round about the city. And the servant said, “Alas, my master! What shall we do?” He said, “Fear not, for those who are with us are more than those who are with them.” Then Eli′sha prayed, and said, “O Lord, I pray thee, open his eyes that he may see.” So the Lord opened the eyes of the young man, and he saw; and behold, the mountain was full of horses and chariots of fire round about Eli′sha. (2 Kgs 6:15-17)

If we ever find ourselves frightened by Satan and his demons, we should remember Elijah’s confidence in his heavenly protectors: “Fear not, for those who are with us are more than those who are with them.”

How the Demons Attack Us

The ordinary way the demons attack us is by trying to lead us into sin. St. Thomas speaks of “the malice of the demons, who through envy endeavor to hinder man’s progress” (ST I.114.1). It is because of this envy that the devil, together with his minions “always tempts in order to hurt by urging man into sin” (ST I.114.2). In trying to hurt us, moreover, the devil often seeks to discover the “inward disposition of man, so that he may tempt him to that vice to which he is most prone” (ST I.114.2.ad2).

To understand the role the devil and his surrogates play in our lives, it is important for us to remember that, even after Christ’s coming, the fallen angels still maintain a large degree of power and authority in the material world. This power and authority is strengthened by human sinfulness, which continually extends Satan’s reign in the world. Every time we commit a sin—particularly a mortal sin—we surrender a part of our soul to the influence of the demons.

Jesus warns us of this enslaving effect of sin: “Truly, truly, I say to you, every one who commits sin is a slave to sin” (John 8:34). The first epistle of John goes even further: “He who commits sin is of the devil; for the devil has sinned from the beginning.” The verse then adds: “The reason the Son of God appeared was to destroy the works of the devil” (1 John 3:8).

When the book of Wisdom explains why death entered the world, it speaks of the spiritual death experienced by those who are part of Satan’s kingdom:

for God created man for incorruption,

and made him in the image of his own eternity,

but through the devil’s envy death entered the world,

and those who belong to his party experience it. (Wis 2:23-24)

St. Thomas clarifies that while not all sins are prompted by the devil (some are prompted by the world or the flesh), nevertheless all sin ties us to the devil in some respect:

When man commits sin without being thereto instigated by the devil, he nevertheless becomes a child of the devil thereby, in so far as he imitates him who was the first to sin. (ST I.114.3.ad2)

Interestingly, St. Thomas also observes while there are some evil actions which are not prompted by the demons, all good actions are in some way supported by the ministry of the angels:

Man can of his own accord fall into sin: but he cannot advance in merit without the Divine assistance, which is borne to man by the ministry of the angels. For this reason the angels take part in all our good works: whereas all our sins are not due to the demons’ instigation. (ST I.114.3.ad3)

God has set up the world in such a way that the angels play an indispensable role in mediating His graces to the rest of creation.

How the Angels Protect Us

We are now in a better position to see how the angels and demons fight one another, despite the fact that they don’t have physical bodies. When Lucifer led his revolt against God, the angels fought one another using intellectual arguments. Since that day, angelic warfare has largely consisted in the fight over the eternal destiny of human beings.

Instead of firing missiles at one another like modern nation states, the angels and demons fight constantly over the souls of men. Driven by envy, the demons hate human beings; they hate how weak and unintelligent we are, and how much we are loved by God. They do everything in their power to lead us into sin; and the more we cooperate with their efforts, the more leverage they gain over our souls.

But the assaults of the demons do not go uncontested. Against the forces of darkness stand the forces of light: St. Michael and his battalions of holy angels who work day and night for the salvation of us sinners.

While the holy angels do not fight the demons using hand-to-hand combat or anything of that sort, they do counter the demons in at least three ways:

1. They petition God to rebuke the demons and to restrict their power in the world;
2. They inspire, enlighten, and encourage us away from sin and towards holiness;
3. They tirelessly intercede to God to send us additional graces to help us on our earthly pilgrimage.

To the holy angels we therefore owe a profound debt of gratitude. More than that, we owe them our active cooperation, as well as our sober acknowledgement of the perennial spiritual war which is being waged all around us. For in that cosmic life-and-death struggle over the eternal fate of every human person, it is our souls which are the battleground.

Further Reading

Fr. Vincent Lampert, Exorcism: The Battle Against Satan and His Demons (Emmaus Road Publishing, 2020)

John Saward, World Invisible: The Catholic Doctrine of the Angels (Angelico Press, 2023)

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.