Woe to me because of my injury! My wound is incurable! Yet I said to myself, "This is my sickness, and I must endure it." (Jeremiah 10:19)
He called his twelve disciples to him and gave them authority to drive out evil spirits and to heal every disease and sickness. (Matthew 10:1)
I have had a headache and sinus drainage for about a day, so of course this morning I did a search on the word "sickness." I'm also taking a class on healing, so this makes for good homework as well. :)
I found it really interesting, what verses came up. On the one hand God says he will heal his people from sickness if they follow him (likewise they will get sick if they don't). And then there are first-hand accounts of healing, but also a few verses which could support the theory that God still sends us sickness today, to recompense for something we have done. And, as Jeremiah states above, we must endure it.
I think a large number of people could take that verse to think that yes, God has meted out punishment for some wrong-doing, and so we must accept it. But I don't think that's what he's saying. I believe that "endure" means "withstand," not "accept willingly." Besides, if you take it in context, Jeremiah is speaking a prophesy, which allows for metaphor. We must not always take literally the words in the Bible.
Continue on to Matthew, and I believe you will see God's preferred position on sickness--healing it. Jesus gave his disciples the authority to heal every kind of sickness. EVERY kind. Cancer, heart conditions, blindness, headaches, cramps, jaundice... and he did not say "you can cure anything except where God has punished someone with sickness." No, Jesus said go and do.
So if you are sick, inquire of the Lord. Perhaps a sickness is a direct result of something we have done (lung cancer from smoking, a headcold from not sleeping enough and allowing the immune system to weaken), but God does not say that we must suck it up and live (or die) with it.
Likewise pray for healing from the people you know. It can happen, no matter how impossible the situation may seem. Remember that God wants us to be pure and whole. Be healed, in the name of Jesus.