Demons and unclean spirits

P. Heavyside

"Jesus believed in demons"

  1. Many people in the time of Jesus believed that demons1 are evil spirits that live in opposition to God and that they cause catastrophes in the world such as earthquakes and illnesses.

  2. Many people today share this view and point to the fact that Jesus cast out demons from men and women as evidence that “Jesus believed in demons”.

  3. Perhaps the most infamous example of Jesus casting out demons to which people refer to prove that “Jesus believed in demons” is the incident of Legion recorded in Mark 5 and Luke 8. Pointing to this incident, it is argued that only a tortuous reading of these texts can deny that demons really do live and wreak havoc against men and women; on the contrary, it is averred, a “simple and straightforward reading” of this incident can only be that for Jesus demons really do live.

  4. In this study we’re going to consider what Jesus taught about demons principally by examining Mark 5:1-20; that is, we’re going to the heart of the proof that demons live and work evil to test whether this is true. For a reason that will become obvious we will see that the pattern of interpretation of Mark 5:1-20 establishes how we can interpret all descriptions of casting out demons in the new testament. In passing, we should note that the “demons” in Mark 5:12 are referred to as “unclean spirits” in Mark 5:13. Thus we can see that in the new testament “demons” and “unclean spirits” have an identical reference.

  5. In this study, we will also ask and answer why “demons”, which is an expression which occurs frequently in the new testament, only occurs very rarely in the old testament (see 18).

Miracles of healing

  1. To understand scripture’s teaching about demons, we need to understand the purpose of miracles of healing in Jesus’ work of “teaching in the Jews’ synagogues… preaching the gospel of the kingdom of God, and healing all manner of sickness and all manner of disease among the people” (Matt 4:23).

  2. Matthew describes this continuing work of the Lord Jesus when he says: “When even was come, they brought to him many that were possessed with demons: and he cast out the spirits with his word, and healed all that were sick” (Matt 8:16). Helpfully, one purpose of these miracles is explained in this context of the work in Bethsaida: “that it might be fulfilled which was spoken by Isaiah the prophet, saying, Himself took our infirmities, and bare our sicknesses” (Matt 8:17).

  3. So a purpose of the miracles of healing was to fulfil a prophecy found in Isaiah 53:4. But what was being fulfilled? We look in vain in this chapter of Isaiah for prophecies about miracles of healing. Isaiah 53: 4 reads: “Surely he has borne our griefs and carried our sorrows” and these words are found in a chapter which is very well known as a prophecy about the suffering of the Lord Jesus Christ for the salvation of man. Of many new testament examples, 1 Peter 3:21-25 quotes extensively from Isaiah 53 to describe this work of the Lord for us.

  4. Consequently, we need to ask why the miracles of healing are said to fulfil Isaiah’s prophecy about the salvation accomplished through Christ’s perfect holiness, his sacrifice and his resurrection from the dead. The answer lies in recognising that the miracles are themselves a parable of the work of salvation. This is illustrated by the fact that the Greek word for salvation, as in “he shall save (sōzō) his people from their sins” (Matt 1:21), is sometimes used of miracles of healing. We will see an example of this below; see 20. That miracles of healing are parables of salvation is also seen from Jesus’ work in Mark 2:1-12 when Jesus taught in a parable, through the healing of the man sick of the palsy, that he had authority on earth to forgive sins.


  1. When Jesus commenced his teaching by parables with the purpose that those that are outside, “seeing may see, and not perceive”, he said to his disciples: “do you not know this parable [of the sower]? and how then will you know all parables?” (Mark 4:12,13). In this, Jesus makes it plain that when he provided the interpretation of “the parable of the sower”, he was laying out a pattern by which the disciples would be enabled to interpret the other parables that he taught. By knowing “the parable of the sower”, they would then know all parables.

  2. Given that, as has been demonstrated, miracles of healing are parables, then if we can interpret one of the incidents of casting out demons, then we will have a pattern by which we can know all parables about demons. Furthermore, since miracles of healing are parables then, clearly, we ought to apply the same interpretive methods to casting out demons as Jesus applied to “the parable of the sower”. These methods included interpretation, expression by expression, of the elements of the parable to determine each expression’s significance. Although it is outside the scope of this study to show this, this was frequently undertaken by reference to old testament sources of each expression in the parable.

A simple reading

  1. So we’ll turn our attention now to the incident involving Legion and we’ll concentrate on the record in Mark 5:1-20. Let’s firstly apply a “simple and straightforward reading” to this text to discover if the narrative withstands such a scrutiny. Of course, those who argue for a “simple and straightforward reading” insist that this incident proves that Jesus believed that demons live and work evil.

  2. We see the demons requesting in Mark 5:10-12 not to be sent away out of the country but to be allowed to enter into the swine. Jesus complies. The demons having entered the swine, what happened? “The herd ran violently down a steep place into the sea… and were choked in the sea” (Mark 5:13). Why? This does not make sense: the demons had requested that they be allowed to enter the swine, why would they then destroy their new habitation; where did the demons go after the swine were destroyed; were the demons committing suicide?

  3. Thus it can be seen that a so called “simple reading” actually presents a serious problem of interpretation. In fact, it results in a narrative that just does not make sense.

Parables of healing

  1. Clearly we need to return to the narrative to explore, in the same manner as Jesus interpreted “the parable of the sower”, what Jesus was teaching. I’ll set out a sample of the expressions in the incident in tabular form and expound their meaning to build up a picture of what Jesus accomplished through this parable:

Mark 5


unclean spirit (v2,8)

The expression “unclean spirit” only occurs in one place in the old testament, in Zechariah 13:2. There we read that “the unclean spirit [shall] pass out of the land”. This occurs when “there shall be a fountain opened to the house of David… for sin and uncleanness” (Zech 13:1) and when the house of David recognises that the wounds in the hands of Jesus their messiah were inflicted by their fathers (Zech 13:6), which is at the time of the establishment of the kingdom in the earth. But note what the “unclean spirit” is associated with in Zechariah 13:2,3: “names of idols… prophets… lies”. This is a set of associations that we will see recurs in the parable of Legion. Thus it is seen in Zechariah 13 quite explicitly that an “unclean spirit” is manifest through lying prophets who cause the people to worship the idols of the nations around about them; “unclean spirit” here simply does not mean a living evil spirit which opposes God.

From this we see that Legion represents the unclean spirit of lying words from prophets who lead the people to the worship of idols.

dwelling among the tombs (v3)

By describing Legion as “dwelling among the tombs” the gospel writer, Mark, makes reference to another old testament prophet as he fills out the picture in the parable. This time it is to the prophet Isaiah, in 65:4, where it is said of the “rebellious people” of Israel that they “remain among the graves2”. Here again we see the condemnation from the prophet for Israel’s failure to worship the true God. They “walk in a way that is not good, after their own thoughts; a people that provoke [Yahweh] to anger” (Is 65:2,3). The latter expression, “provoke Yahweh to anger” is taken from Deuteronomy 32:13 where the cause of this anger is that “they sacrificed to demons, not to God; to gods whom they did not know” (Deut 32:17). We will return to this context later in the study (see 18). Thus, just as the unclean spirit in Legion is associated with lies and false worship, so “dwelling among tombs” is likewise constructed around the worship of false gods. Isaiah tells us who these false gods are: “their own thoughts” which results in these people saying: “stand by yourself, do not come near to me; for I am holier than you” (Is 65:5). Who are these? The Pharisees and their disciples. Who do they worship? Themselves, who, whilst the “tax collector stands afar off”, pray “with themselves” because they “trusted in themselves that they were righteous and despised others” (Luke 18:9).

Thus we see that Legion, dwelling among the tombs, signifies in a parable the “whited sepulchres… full of dead bones and of all uncleanness” (Matt 23:27), the scribes, the Pharisees and those whom they make “twofold more the child of hell than themselves” (Matt 23:15).

bound with fetters and chains (v4)

The foregoing theme of the spirit of false worship continues in the description of Legion being often “bound with fetters” because this takes us to an incident in the captivity of Manasseh when he was taken by the Assyrians “bound… with fetters” and carried to Babylon (2 Chron 33:11). Just as Manasseh was captive in Babylon, so Legion was captive in the land of the Gadarenes (Mark 5:1) in gentile Decapolis (Mark 5:20). Why was Manasseh “bound with fetters”? Because “he reared up altars for Baalim… and worshipped the host of heaven… he caused his children to pass through the fire in the valley of the son of Hinnom… to provoke him to anger [cp. Is 65:3; Deut 32:16]” (2 Chron 33:3-10). Manasseh is described as utterly bound up with the deceptive spirit of the worship of false gods and idols and he is taken into captivity because of this.

Likewise we see that Legion is a figure of Israel taken captive out of the land of promise because of their unbelief and their worship of false gods.

cutting himself (v5)

You will not be surprised to discover that this next expression continues the parable of Legion being a figure of the worship of false gods and provocation of the true God. Legion “cutting himself” draws upon an incident in Elijah’s witness against the deceitful worship of Baal and Asherah. Elijah contested this false worship against eight hundred and fifty prophets of these false gods (1 Kings 18:19). During the invocation of their false gods upon mount Carmel, the four hundred and fifty prophets of Baal “cut themselves” (1 Kings 18:28). We see a kind of madness described in these prophets as they cut themselves to such an extent that “the blood gushed out upon them” (1 Kings 18:28).

Such madness is fittingly represented by the wrong-minded Legion. This is a madness manifest by the false and self-worship of those who trusted in themselves.

we are many (v9)

This next expression that I have selected for exposition reinforces the earlier identification in this parable of Legion with the scribes, the Pharisees and their disciples. It is an expression which also resonates with the situation on mount Carmel where Elijah said: “I, I only, remain a prophet of Yahweh, but Baal’s prophets are four hundred and fifty men” (1 Kings 18:22). “We are many” is quoted from Ezekiel 33:24 where the son of man witnesses to a prophecy about the Jews in Jesus’ day. Ezekiel testifies: “they that inhabit… the land of Israel speak, saying, Abraham was one, and he inherited the land: but we are many; the land is given us for an inheritance”. Here are those, the Pharisees and Sadducees, who say within themselves, “we have Abraham to our father” (Matt 3:9); the Jews who say, “we be Abraham’s seed and were never in bondage to any man” (John 8:33); those who trusted in themselves through their numerical standing and thus who completely disbelieved in the grace of God. As has been demonstrated earlier, this amounted to self-worship through the spirit of lying words. Ezekiel addresses this state of affairs earlier in his prophecy when he records that “the elders of Israel” who sat before him had “set up idols in their heart” (Ezek 14:1,3). Strikingly, Ezekiel is caused to witness against them because of “the multitude of… idols” (Ezek 14:4) in the hearts of the many in Israel (the Hebrew word for “many” in Ezekiel 33:24 is the same word as is translated “multitude” in Ezekiel 14:4).

Thus we see that Legion stands for the many in Israel who had forsaken the mercy and truth of God for the false self-worship of the Jews, those who believed that they could attain to salvation as a debt for works.

swine feeding (v11)

The final expression I have picked out returns us to Isaiah 65:4 because we see there that they that dwell among the tombs eat “swine’s flesh”. The consumption of “swine’s flesh” in Isaiah 65 is part of the false worship practised by those who provoke Yahweh to anger. Thus the swine are part of the demonic madness of choosing to worship idols in their own hearts rather than the living God.

In the incident of Legion, Jesus strikes a magnificent identification of the swine with the demons when he sends the demons into the swine; both the demons and the swine stand for the wrong-mindedness of those Jews who trusted in themselves. And the magnificence of this identification is continued by showing in both that the end for all such Jews is as though they run “violently down a steep place into the sea” and choke (Mark 5:13).

A lie in my right hand

  1. The parable of Legion and his demons and the unclean spirit is clearly a description of those Jews that had forsaken the mercy and grace of God through a worship of themselves in believing that they could earn life from God as a debt. The demons and the unclean spirit represent their false teaching which sets up idols in their own heart. Whilst these Jews enthusiastically believed their own deceptions and worshipped these idols, as Paul says: “We know that an idol is nothing in this world, and there is none other God but one. For though there be that are called gods… to us there is but one God” (1 Cor 8:4,5). Thus no matter how much a person may believe in an idol and a god, it makes no difference to the truth that God is the one and only God.

  2. Some may feel uncomfortable with the notion that the strength of belief they see in those who fear demons is merely vanity. But we should note how Isaiah describes those who fear idols and how such belief can only be described, as with Legion, as a kind of madness. This description is in Isaiah 44:9-20; let’s summarise what he teaches there about these worshippers of idols:

    • they make the idol “after the figure of a man, according to the beauty of a man; thus they merely create the imaginations of their own heart, where the spirit of the idol is set up (Is 44:13);

    • they use one part of a tree to warm themselves and to bake bread and use another part of the same tree to make a god and worship it; they even fall down and pray to the graven image saying, “Deliver me; for you are my god” (Is 44:15-17);

    • none of them considers the foregoing and reasons how mad they have become (Is 44:19); why?

    • because such is the power that the graven image exercises over the minds of the worshippers that he “has shut their eyes… and their hearts” (Is 44:18); the worshipper has become so consumed by the imaginations of his own heart that he is deceived in his heart, he cannot say “is there not a lie in my right hand?” (Is 44:20).

  3. It is at this point that we can now reflect on the question we flagged earlier: why does “demon” occur frequently in the new testament and only rarely in the old testament? Because in the old testament this spirit of falsehood is externalised much more regularly in graven images and idols. In the new testament, some may have turned their backs on external images and idols, but their worship of idols in their hearts was just as prevalent internally as it had been external in the old testament. And one of the old testament passages to which we have referred several times strikes this identification of internalised demons and externalised false gods most forcibly. Deuteronomy 32:17 says that Israel, “sacrificed to demons, not to God, to gods whom they did not know”; and Paul confirms this for us when he quotes these words when speaking of that which is offered to idols in 1 Corinthians 10: “the things which the nations sacrifice, they sacrifice to demons not to God” (1 Cor 10:19,20).

Clothed and in his right mind

  1. The parable of Legion does not, of course, leave us just with this terrible picture of the choking death of those who turn their backs on God.

  2. Legion “was saved” (Luke 8:36, where the word for “healed” translates the word for “save” in Matt 1:21). What was the turning point? What caused Legion to be saved? We see a wonderful confession from Legion during this parable; he called Jesus “son of the most high God” (Mark 5:7). Because of this he was saved from his shameful nakedness (Luke 8:27, “wore no clothes”) to be clothed (Mark 5:15) by Christ. He was converted from the madness of his demons and unclean spirit to being “in his right mind” (Mark 5:15).

  3. The same offer was open to those Jews who trusted in themselves. And some will grasp this with faith. They will recognise the one who was wounded in the house of his friends (Zech 13:6) and mourn for the only son (Zech 12:10) so that the shame (Is 44:9,11) of the worship of idols in their heart will pass out of the land (Zech 13:2).


1 In the KJV new testament, “devil” translates diabolos whilst “devils” translates daimonion or a related verb daimonizomai (“possessed of devils”). In these notes, I use “demon(s)” throughout in translations of the latter two Greek expressions.

2 The Greek for “dwelling (katoikēsis)” and “tomb (mnēmeion)” correspond to the meaning of the Hebrew for “remain (yšb)” and “grave (qbr)”.

L Buck,
10 Jan 2009, 05:46