1. "Sin" is the only reason for sickness. If there was no sin in the world there would be no sickness. Get rid of the sin, and you will get rid of the sickness.
All sickness is the results of a spiritual condition. Get rid of the spiritual condition, and the sickness goes away. This is exactly what Jesus taught.
2. Act 10:38 How God anointed Jesus of Nazareth with the Holy Ghost and with power: who went about doing good, and healing all that were oppressed of the devil; for God was with him.
Luk 13:16 And ought not this woman, being a daughter of Abraham, whom Satan hath bound, lo, these eighteen years, be loosed from this bond on the sabbath day?
Luk 5:23 Whether is easier, to say, Thy sins be forgiven thee; or to say, Rise up and walk?
3. Jesus's death on the cross healed a spiritual condition which in turn heals a physical condition. Do we still sin after becoming Christians? Yes we do. What happens if we do? Sickness can be a sign of sin in our lives. Now what? We are to confess our sins, so God will "cleanse" us from all unrighteousness. What if we wont confess our sins? Get ready to go to the doctor, because you just open the door for the Devil to cause trouble in your life. The early Church had this problem, and the Apostle Paul warned them about, and how to fix it.
1Co 11:26 For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes.
1Co 11:27 Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty concerning the body and blood of the Lord.
1Co 11:28 Let a person examine himself, then, and so eat of the bread and drink of the cup.
1Co 11:29 For anyone who eats and drinks without discerning the body eats and drinks judgment on himself.
1Co 11:30 That is why many of you are weak and ill, and some have died.
1Co 11:31 But if we judged ourselves truly, we would not be judged.
Eating and drinking of the Lords cup in a unworthy way is by not discerning the Lords body in how he brought spiritual healing and physical healing to his Church. This is why a lot of them in the Church were sick, and ,many of them died!!!!