I think I'm beginning to understand why God allows (note I said allows, not causes) pain in the lives of his children. It's because, in the deepest hour of our darkness, when nothing and no one offers any help and the agony is greater than we can bear, we are driven to him. We cling to him because he offers life. We hold on to him because he is the only one who offers hope. The very desperation of our situation allows us no other recourse than to throw ourselves on him and hold tight with all our strength.
It builds a tough and tenacious faith. God doesn't want a superficial and easy-going faith, that flippantly praises him when everything is wonderful. He wants a strong faith, a faith that is deeply rooted in him, and as the trials and pressures of life come on, roots itself ever deeper, growing more tendrils, more branches, more strings, to cling onto his rock, to reach out to suck in the nourishment of his soil. It's when I go through the deepest pain, the darkest agony, and he reaches out to grasp on to me, that I know him the most. And that I'm the most thankful to him.
And I'm grateful for it. Not for what causes the pain. That's not a good. But for his grace, which I wouldn't know apart from the pain. That is good.