The Problem of Pain

The first statement in Lewis' chapter on human pain was "God whispers to us in our pleasures, speaks in our conscience, but shouts in our pain; it is His megaphone to rouse a deaf world."  I think this is a really powerful statement because so much of my spiritual growth has taken place during painful times in my life and it reminds me of a song that really helped me get through some hard times in my life called "Beauty from Pain" by Superchick.  Thy lyrics to the chorus are:

After all this has passed, I still will remain
After I've cried my last, there'll be beauty from pain
Though it won't be today, someday I'll hope again
And there'll be beauty from pain
You will bring beauty from my pain

Sometimes our "deserts" can seem overwhelming and it can feel like God is just out to get us.  I've struggled a lot with resentment toward God for making me go through so much pain in my life while some people never have to deal with anything.  My school guidance counselor told me that God was putting me through those things to teach me something that would be really important in my vocation and maybe not as important in someone else's vocation.  This can seem really obnoxious-like, why can't God teach me patience by giving me an untrained puppy?  But I've come to find out that the things that you remember often come with some sort of extreme experience-good or bad.
     The other thing that stood out to me from this writing was "we cannot therefore know that we are acting at all, or primarily, for God's sake, unless the material of this action is contrary to our inclinations or (in other words) painful."  This seems to contradict what Lewis said in his Our English Syllabus when he was talking about how God gives us passions for certain things and pursuing those passions are often following his will.  These two contradictory statements left me in a very confused state and have me questioning what I'm doing here are Calvin.  I don't really know what to take from that statement.