God doesn't promise healing. Jesus rose the dead to life. Gave sight to the blind. Made the deaf hear and the dumb speak. My wife suffered for years before dying at the age of 30. There wasn't any magic healing for her or anyone else that I've ever known. The Bible doesn't promise that. Even Timothy was frequently sick and not miraculously healed.
(1 Timothy 5:23 NIV) Stop drinking only water, and use a little wine because of your stomach and your frequent illnesses.