The simplest healing scripture I can think of is Isaiah 53:5 "But he [was] wounded for our transgressions, [he was] bruised for our iniquities: the chastisement of our peace [was] upon him; and with his stripes we are healed." But I have been told that the last part is simply referring to being healed from our sins. Well guess what, I wasn't healed from my sins, I was forgiven of them. So to prove that God really has saved us from everything, I did some research to find out what the word "saved" really means. John 3:17 says this: "For God sent not His Son into the world to condemn the world; but that the world through Him might be saved." The last word in that verse is the Greek word sōzō, and the definition is as follows:
1) to save, keep safe and sound, to rescue from danger or destruction
a) one (from injury or peril)
1) to save a suffering one (from perishing), i.e. one suffering from disease, to make well, heal, restore to health
1) to preserve one who is in danger of destruction, to save or rescue
b) to save in the technical biblical sense
1) negatively
a) to deliver from the penalties of the Messianic judgment
b) to save from the evils which obstruct the reception of the Messianic deliverance
So a huge part of the definition refers to physical healing. You may also find it interesting that this same Greek word is used in the story of the woman with the issue of blood when Jesus says to her "thy faith hath made thee whole."
On the prosperity issue, take a look at Romans 10:12: "For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him." The word "rich" used in this verse means:
1) to be rich, to have abundance
a) of outward possessions
2) metaph. to be richly supplied
a) is affluent in resources so that he can give blessings of salvation to all
I've heard people say that our sickness, poverty, and death bring glory to God. It is so backwards to blame your troubles on God, and it just gives you an excuse to not use your faith. God has given us the power we need to resist all attacks of the devil, and then He gets the glory in the end because our faith has made us victorious. Jesus took it all to the cross, and it is totally up to you to receive everything that Christ died for you to have, from your salvation to healing from a headache.