I was reading today from a Thomas Howard anthology, and came upon this passage in an essay entitled the Image of the Cross:
And the faithful can only answer that the Christian mysteries are full of rich and staggering paradoxes, and that in the case of the Cross, the eye of faith sees the worst thing that ever happened (deicide) to be the best thing that ever happened (salvation), and the most appalling instrument of torture to be the very thing to which we cling for our refuge and joy. A similar paradox is uttered in the ancient formula "O felix culpa Adae" (O happy fault of Adam), the idea being, not that we laud sin, but that that sin became the occasion for the greatest thing of all (Grace) to manifest itself.
I believe that at the ends of our days, we will look back on our lives and state emphatically that the worst thing that happened to us was transformed into the best thing that happened to us, because it was the instrument through which God's grace poured out onto our lives most fully and completely.
That will be the essence of the book I plan to write, talking about things in my life that for a long time I wished I had never experienced. I can now say, like that blind Carthusian, that God allowed my particular challenges for one purpose: the betterment of my soul. I can only say that's evidence of God's grace moving in my life, and for that I'm grateful.