When Jesus healed people whose health was affected by a demon, he treated them differently.
He delivered a boy from epilepsy (Luke 9:37ff). And he released a woman from a spirit of infirmity (Luke 13:10ff).
He didn’t pray for them. He tackled the evil spirits, and then they were healed.
If your sickness is caused by a demon, you won’t get better unless it is kicked out in Jesus’ name.
Some Christians say they can’t ‘have’ a demon. This is true. They cannot be ‘possessed’ if Jesus is truly their Lord.
But the Greek word for ‘possession’ is about influence, not ownership. And demons can most certainly influence a believer’s health.
The woman with the spirit of infirmity was a believer, a synagogue attender and had such faith that Jesus called her a daughter of Abraham.
But the enemy had still afflicted her with a back problem for 18 years.
People who don’t accept what the bible says on this subject of usually have two choices. They can repent of their unbelief, or remain sick.
Not all sickness is demonic. But some is. And if God has not healed you, then ask someone with discernment to pray with you.
The gates of hell will not prevail against their prayers.