Are Illnesses Caused by Demons?

The Bible speaks regularly about demons, and about the healing of physical illnesses. Sometimes, both are included in the same verse. Some conclude that demons cause illnesses, and that casting out the demons will heal the illnesses. Is this true?

First, let’s agree that demons aren’t the cause of ALL illnesses. While some believe that all illnesses are caused by demons, and some believe that all illnesses are the result of negative thinking (or a lack of faith), these are fringe views with very little to commend them. Some even speak of an illness as ‘having a spirit of influenza’ or ‘having a demon of cancer.’

Can demons cause any illness at all? Speculation in this area simply can’t provide a definitive answer, so we rely on Scripture – and Scripture alone – to determine what can be known. If the Bible tells us that demons can cause illnesses, we will have our answer. If the Bible does not, we should be content in acknowledging what Scripture does not teach.

One verse cited as evidence that demons cause illnesses is Acts 8:7: For with shrieks, impure spirits came out of many, and many who were paralyzed or lame were healed.

The repetition of “many” shows that these are different groups of people. Many had demons, and many were paralyzed or lame. There’s no reason to connect the groups and claim that the physical problems were caused by the impure spirits. The text itself doesn’t connect them.

Let’s take a look at the literal Greek translation from the KJV. The original word order is a little different: For unclean spirits crying with loud voice came out of many that were possessed with them and many taken with palsies and that were lame were healed.

Again, the text indicates that the demon-possessed were seen as a separate group from those who were physically ill. Let’s see what the NASB says, as many consider it the best word-for-word translation: For in the case of many who had unclean spirits they were coming out of them shouting with a loud voice and many who had been paralyzed and lame were healed.

It seems clear that this passage does not connect demonic activity with physical illness.

Here’s Acts 19:12: God did extraordinary miracles through Paul, so that even handkerchiefs and aprons that had touched him were taken to the sick, and their illnesses were cured and the evil spirits left them.

At first glance, it appears that this verse may connect the two… but when we look closely at the original language, the connection seems weaker. Literally. The word translated “sick” is the Greek ASTHENEO. It’s more flexible than “physically ill.” Here’s what ASTHENEO means:

• to be weak, feeble, to be without strength, powerless
• to be weak in means, needy, poor
• to be feeble, sick

Who are “the sick”? Sometimes ASTHENEO means “physically ill,” but it’s used differently in different passages:

• In John 5:3, it’s used to describe people who are blind, lame, and paralyzed.
• In Acts 20:35, Paul uses it to talk about giving to the poor.
• In Romans 8:3, it’s used to describe the weakness of the law.
• In Romans 14 and 1 Corinthians 8, it’s used to describe weak faith.
• In 2 Corinthians 8:12, Paul uses it to refer to foolishness.
• In 2 Corinthians 12:10, Paul uses it to describe stresses like insults and persecutions.

While it’s theoretically possible that Acts 19:12 refers to demons making people ill, it’s not clear. At best, this verse MAY imply it, but that’s not enough. One of the primary principles of biblical interpretation is that we use clear verse to interpret unclear verses, and that we don’t make doctrines from unclear passages.

We might take the word “sick” to refer to two groups of people who were afflicted… one group demon-possessed and the other physically ill. On the other hand, we might take “sick” to refer to one group, who were made sick by evil spirits and healed by casting them out. Without more information, we can’t draw a conclusion.

A third situation in the New Testament comes from three of the gospels: Matthew 17, Mark 9, and Luke 9. A boy was possessed by a demon, and sometimes lost control of his body. He couldn’t then speak, and the demon would cause the boy to fall into a fire or into some water.

A few translations of the Matthew passage use the word epilepsy to describe the boy’s affliction. This seems unfortunate, as the ancient Greeks didn’t know about epilepsy. The Greek word means to convulse, or to tear. It’s an action, not a condition. I couldn’t find any translation that rendered the word as epilepsy in either the Mark or Luke passages. When we combine the three passages to learn as much as we can, it seems that when translators interpreted the Matthew passage, they may have assumed too much.

What we do see in Scripture is that demons can cause physical problems, as with the boy’s convulsions. In Luke 13 we see a woman with a demon who had been bent over for many years. After Jesus cast it out, she was able to stand upright. Some, like the boy, were rendered mute, and others blind or deaf. There’s no question that being demon-possessed can cause physical problems, at least temporarily.

However: these physical problems are not illnesses or diseases. The afflicted may have lost control over their bodies, but that’s not the same as demons giving people cancer, or the flu, or COVID. In fact, when the New Testament writers speak of healings, they almost always describe the demonic as separate from other kinds of problems:

• In Matthew 10, Jesus sent the disciples out to “heal the sick, raise the dead, cleanse those who have leprosy, drive out demons.”
• In Luke 4, “people brought to Jesus all who had various kinds of sickness, and laying his hands on each one, he healed them. Moreover, demons came out of many people…”
• In Luke 7, “Jesus cured many who had diseases, sicknesses and evil spirits, and gave sight to many who were blind.”
• In Luke 9, Jesus gave His disciples “power and authority to drive out all demons and to cure diseases.”
• In Luke 13, Jesus said “I will keep on driving out demons and healing people today and tomorrow.”
• In Acts 5, crowds brought their sick and those tormented by evil spirits.

While it’s clear that demonic activity can cause physical problems, the Bible is not clear that demons can cause physical illnesses. The evidence seems to point in the other direction, as I can find no passage where demons are responsible for that kind of problem.

What are your thoughts? Can you find any verse that directly ties physical illnesses like colds or cancers to demonic activity?

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