You were healed because Jesus already bore the stripes for your healing. Go on to verse 18 because I want to point out something about hope. Who against hope believed in hope, that he might become the father of many nations, according to that which was spoken, So shall thy seed be. Hope is always future. It is not wrong to talk about the future.
Some people think it is wrong to confess when the prayer of faith is going to manifest.
So shall thy seed be. If it is wrong to talk about our hope, we could never talk about the rapture. We could only say that we are seated with Him in heavenly places in Christ. That is our faith speaking. There is a natural, human faith and a supernatural faith.