Somewhere along the way we got this idea that God is really interested in giving us a good, easy life. That he wants us to be happy. That he wants us to deal with the least amount of pain possible. That suffering has no part in his will for our lives.
Maybe those things are true, but the reality of the world that I live in, and the reality of the person that I am, is that there are parts of my deep heart that are violently opposed to God. There are yet-unredeemed parts of my being that rage against God when things don't go the way I expect they should go, or when I don't get what I want, or when I perceive that God has not delivered on a promise that I tried to manipulate him into making to me. Sin is simply a part of who I am, and it will take God at least the rest of my natural life to transform me into the image of his Son.
Transformation is painful. It's one thing to give up some sin that you don't really care about, it's another thing altogether to repent of the ways in which your very personality, and way of thinking, has been corrupted by the sins you commit and the sins committed against you. That's the transformation that leaves a mark on your character.
God is good. And I've got the scars to prove it.
This is a sort of paraphrase of the things that Paul wrote about his own life with God to the many churches that received letters from him. God hit Paul where it hurt him most time and again. He even once said to a man about Paul, "I will show him how much he must suffer for my name." He's done that with many of the great saints of church history.
God wounds us because only by being wounded can we move through healing toward godliness.
Suffering is the definitive mark of a disciple of Jesus. After all, we follow the one who was crucified on our behalf. And like what Jesus suffered on the cross, the suffering we endure will one day be redeemed by our Heavenly Father.
I believe that God is currently trying to root out all the sinful desires, all the idolatry, and all the wickedness from your heart. That's what he's doing to me. And it hurts. But he's doing it in order to make us like his Son. He's doing it because he's good; I've got the scars to prove it. And if you stick with God long enough, if you stick with him through the crap of your life and engage with what he's doing in the midst of it, you too will be marked with the scars that prove the goodness of God.