The question has arisen as to whether God, the creator of all things, is the creator of disease. I believe the answer to this to be NO. I would like to reference the book of Job as my reasoning behind this. God and satan were conversing in chapter 1, and God says that Job fears God. Satan challenges God by saying that Job is untouchable because God has put a shield of protection around him. God agrees to withdraw his protection but tells satan he can not touch his servant Job. Satan causes servants to be slaughtered, fire to rain down from heaven, and wind to destroy his house. Still Job is faithful to God.
Chapter 2 of Job says that satan and God conversed again and satan complains that unless he can pursue bodily harm on Job, he has no chance of cursing God. God then says that he will remove his hand of protection off of Job, but that satan must spare his life. So satan goes out and strikes Job down with painful sores from the soles of his feet, to the top of his head.
We can see that the boils did not come from God. The fire, wind, and murders did not come from Him. They were derived from satan. You can make a case in Exodus of the Egyptians being struck down with the plagues from God. My argument to that is that God is capable of anything. He is almighty, and all powerful. The plagues were their judgement for pharoah's disobedience to God. Satan is only allowed to do what he does, because God allows him to.
Bottom line is that due to the curse of man in the Garden of Eden, we live in a sinful fallen world. This is not the life that God intended for man to live. He did not intend for man to toil by the sweat of his brow while working, or for women to have pain in childbirth. It is not His intent that any should suffer or perish, but have everlasting life through Him. Where the conundrum lies, is in the fact that Good People Die. Why is this? Some things we will never know the answer to. One thing I am certain of, is that we will not cease in our tears or mourning until we are in heaven. Sorrows will follow us on this earth, as this is the curse of Adam.
Some of my Pentecostal/Charismatic friends make the case that cancer and other dreaded diseases are demons, and thus should be cast out. Further yet, some of my holistic friends make the case that we have the diseases on this earth today because of the diets that we eat, and all the chemicals and pesticides in the earth. Still, I have heard the case made that Aids is God's curse on homosexuals. Whatever the case may be, satan is roaming through this earth seeking whom he may devour. I am sure of the fact that the demonic is real, but am not sure that you can cast out a demon of cancer. I am sure that we have way too many pesticides and chemicals in our soil, but not sure that we would ever be able to rid ourselves completely of all toxins.
One thing that I am sure of, I will continue to pray for God's divine intervention in peoples lives. If they are healed, then so be it. If they die, then so be it. I do not believe that because somebody wasn't healed, it is a lack of faith on their part. On the flip side, I do believe in Divine Healing, and know that God can also heal us by taking us home. Please do not mistake this with people saying "God just needed them in heaven more than we did on earth." No he didn't. He does not Need us. People die... It is not fair... Wake up and realize that we will not be WHOLE and PERFECT until Jesus' return. MARANATHA... Come soon Lord Jesus!!!