No, not all healings are from God’s direct hand. We can have natural healing that is due to how God designed our bodies to heal themselves. We can have healings that are the result of medicine. And, of course, there are healings that are demonic.

“Many will say to Me on that day, ‘Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?’ 23 “And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness,’” (Matthew 7:22-23).

We can see in this section of Scripture that Jesus there were those who were able to cast out demons and perform miracles but were not Christians. There is no reason to exclude physical healings from the context of casting out demons and performing miracles. We can see in the New Testament that some healings were the result of casting out demons.

• “And as they were going out, behold, a dumb man, demon-possessed, was brought to Him. 33 And after the demon was cast out, the dumb man spoke; and the multitudes marveled, saying, “Nothing like this was ever seen in Israel,” (Matthew 9:32-33).
• “Lord, have mercy on my son, for he is a lunatic, and is very ill; for he often falls into the fire, and often into the water. 16 And I brought him to Your disciples, and they could not cure him. 17 And Jesus answered and said, “O unbelieving and perverted generation, how long shall I be with you? How long shall I put up with you? Bring him here to Me.” 18 And Jesus rebuked him, and the demon came out of him, and the boy was cured at once,” (Matthew 17:15-18).

So, we can safely conclude that some miraculous healings can be demonic in origin.

So why would there be healings that are not of God but, as would seem, from demonic origin? It would be because the demonic forces, if and when they heal someone, could help that person believe in something false. For example, let’s take a Mormon who believes in a false god and prays to his god for healing and the healing occurs. That would be demonic activity at work for the purpose of further deception.