"[Pain] removes the veil; it plants the flag of truth within the fortress of a rebel soul." C.S. Lewis, The Problem of Pain
There are times in life when we know why we suffer. It is clear that we do something wrong and we have to pay the consequence for it. Sometimes, however, the natural question is, "why?" God is supposed to be a shield, yet it seems like He is anything but protecting us. God is supposed to walk beside us, but sometimes it is like He is hiding His face. I think a lot of times, the main reason that we suffer is because of our rebel souls. Ever notice how those of us who are hard headed (I wonder if I should rather have written hard hearted) suffer more than others? It is because our hearts are not submitted to God that God has to allow suffering in our lives. A flag needs to be planted in our hearts.
The other aspect of this is the veil that we often live with. Until we suffer pain, we do not realize the extent of the black condition of our hearts -- how dishonest we are, or rebellious, or proud. The crucible of suffering reveals the impurities like nothing else.
Pain is truly a "necessary evil". I am not a masochists that seeks pain, yet we always need to remind ourselves that our pain serves good purposes. If you are going through a rough time right now, submit yourself to God. Submission while gong through a hard time is difficult because submission involves trusting, and it is difficult to trust when our circumstances would indicate something else. Yet, the sooner we submit, the less we will have to suffer.