Jesus came to earth and gave Himself as a sacrifice for sin in order to buy back for you everything that Adam lost. He came to destroy all the works of the devil...sickness and disease included. Once you receive Him as Lord of your life, all the rights and privileges God originally intended you to have (the right to things like fellowship with God, health and prosperity) are restored.
But you are the one who has to exercise those rights!
You see, the devil is an outlaw and even though Jesus has taken away his authority in the earth, even though he has no legal right to kill or steal from the children of God, he’ll do it anyway...as long as you’ll let him get away with it.
You must enforce his defeat by speaking the Word of God in faith. Act on His Word now. Demand that sickness and disease leave you in the Name of Jesus. Then refuse to back off that demand. Resist the devil with all you’ve got. He might fight you for a while, but sooner or later, he will have to flee from you!