Just to make your case stronger, how could you ever thank God for healing you from a sickness when He was the one who caused you to be sick? How could you properly thank Him for saving you from a dangerous situation when He was the one who put you there in the first place? How could you thank God for any good fortune you have when He caused the bad fortune that preceded it?
The bottom line lies in the fact that you don’t see the entirety of God’s “books.” He has his chesbonos about what is good and what is bad. Perhaps you “needed” the illness that He gave you for some reason — to teach you a lesson, to provide you with an opportunity for personal growth, to inspire you to work towards a cure for your illness, or even just to help yo atone for some previous sins. The same could be said for any “misfortune” that you suffer.
If you define God as One who is good and One who provides good, then, in the end, all that happens is for your benefit. Yes, you may not see it and, admittedly, there are circumstances where it may be impossible for us mortal humans to comprehend how a misfortune is good; but in the end, if you work with the above definition, then it has to be good. Perhaps that is why we are commanded to bless God for the bad as well as the good.
Being the tech geek that I am, I like to think of God sitting there with a giant Excel spreadsheet* with which He governs the world. We, however, only have a view of a few cells on the spreadsheet. Sadly, the results that we see are based on variables that are in cells on His spreadsheet that we cannot see. As a result, something that seems bad may, in fact, be good.
* I’m not sure which is more blasphemous — the idea that God uses computers or that He would use a Microsoft product. 🙂
(Of course I don’t believe that God uses computers… it’s just a metaphor!)