Liberty
"... unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness." - Declaration of Independence
Alan Keyes, during a Q&A after a talk touched on the Liberty aspect and laid bare the foundations with such clarity... he said (not the eloquent original text): If God himself saw fit to give men freedom we should be most reluctant to reverse that endowment!
So what happens when you give every person freedom? Evil. Yes - some evil will undoubtedly happen in the world. To prevent it wouldn't God have to rescind free will?
St. Augustine defined evil as the lesser of two goods. (This takes some time to get used to but it is based on the simple fact that what God made (created things) are objectively goods.)
So how do you give freedom to every living person? You have to allow for each person to see the various choices available to him - to be able to weigh them according to their different attributes and consequences - and to make the choice based on that stew. Someone who always makes the choice which brings him alone the most pleasure (at the expense of others' or even God) is a hedonist. Someone who always makes the choice which brings him alone the most power (at the expense of others or God) is ambitious (in the bad sense). Someone who genuinely works to make the choice that is THE best available (with respect to God, others and himself) is a saint. Etc.
So every action must touch on several attributes and consequences. We must live in a web with other creatures and with God.
Therefore it seems that God will not remove all hurts and obstacles and ornery folks precisely because He wishes to preserve in us the dignity of Liberty.