I suppose one of the hardest questions to answer is: "Why do I have to deal with so much adversity?!"
Quite honestly, one of the best answers I've ever come across was written by C.S. Lewis in his book, Mere Christianity.
Lewis likened God's use of adversity to walking a dog.
If the dog gets its leash wrapped around a pole and tries to continue running forward, he will only tighten the leash more. Both the dog and the owner are after the same end: forward motion.
But the owner must resist the dog by pulling him opposite of the direction that he wants to go.
The master, sharing the same intention, but understanding better than the dog where he really wants to go, takes an action precisely opposite to that of the dog's will...