Thank you for engaging on that, Cinder
I agree that those more scholarly than myself have drawn the conclusion of it being a physical issue, perhaps even an actual thorn that had become embedded in his flesh, perhaps the lasting result of a beating he suffered for choosing Christ, perhaps any number of things...and what it was specifically is not something that I need to know, because I can take lesson from it without the details.
I think that whether it be illness, addiction, fiscal woes, or other hardship...that just because we earnestly ask God to change a situation that it does not mean he will. I am not boxing God - He CAN do anything, so let's not have anyone accuse me of that. But rather, I believe that God sometimes places these things in our lives to refine us or to prepare us to be used as His instrument in a situation. There is nothing good about a hardship, until God takes the cracked, earthen vessel and uses that imperfection to show His greatness. (2 Corinthians 2 and even 3, if you need verses, ask.) If I am failing to engage in my addiction, but still am tempted by it, then surely God can (and does) use that. I am neither free from temptation, nor free from addiction, but by God's grace, I am empowered by Him to be able to choose to not partake. Some would say that because I am still tempted I am not "in the light." I am of the opinion these people have not known addiction firsthand, but for their sake we shall say I stand in the shadowlands that border day and night. Because I am not engaged in the darkness of addiction, I can hold the lantern high to help show God's light that others may be lead from the depths of darkness. I know better than to place myself in the grasp of further temptation, but rather am there to catch the hand of others as they reach out once they have decided they want to change.
Back to those shadowlands, it is here that God's work is done, where the lukewarm are spat out and where our metal is tested.
Have you ever seen a slaughterhouse knife with the middle of the blade cut out? The leading edge is there to do the cutting, there is a framework at the back that supports and strengthens. The unnecessary parts in the middle have been removed. Some might say to conserve the metal, some cite other reasons. The man using the knife told me that he chose it because it lightened the tool and he could do more work. If I cannot be on the knife's edge, doing God's work, then I must strive hard to ensure that I am part of the framework, supporting those on the front lines.