Even if I should choose to boast, I would not be a fool, because I would be speaking the truth. But I refrain, so no one will think more of me than is warranted by what I do or say. —2 Corinthians 12:6
Paul knew of the possibility that he could be an effective preacher, see people converted, and see people grow, and then he himself could be rejected in terms of a reward. He would be saved, yes, but as by fire (1 Cor. 3:15).
A thorn in the flesh protects you from yourself! That is why God does it. I therefore go this far: it is arguably the best thing that ever happened to us.
The thorn in the flesh is to make up for a deficiency. That is what compensation is. A typical deficiency is the Christlikeness that is lacking in us. God says, "I want you to be more like Jesus, and I have blessed you." If we are totally honest, we know God has been good to us. If He did not send a thorn in the flesh to compensate, who knows what we would be like!
I can think of many deficiencies that require the thorn in the flesh in my case. For example, I don't have enough faith. I don't have enough love. I don't have enough empathy, caring for others. These are things that the flesh by itself will never bring about. I need an increase in faith, love, and empathy.
How, though, does this thorn achieve its aim? How does it actually keep us from being conceited? The answer is that it protects us from ourselves. If you are like me, you sometimes think, If God hadn't stopped me, I don't know what I would have said or done. I have lived long enough to say, when I see in any other person a weakness, malady, sin, or wickedness, "That's me—except God has kept me." It is what protects us from ourselves.
Excerpted from The Thorn in the Flesh (Charisma House, 2004).