I know, O Lord, that your laws are righteous, and in faithfulness you have afflicted me. —Psalm 119:75
How does the thorn work? Through pain. The thorn is given that we may "share in his holiness" (Heb. 12:10). It is not pleasant; it is painful. A thorn hurts. It gets and keeps our attention.
Why would God inflict us with pain? Keep in mind that this thorn doesn't kill us; it only hurts us. The pain is necessary because God's glory is a no-joke thing. He is determined that no flesh will glory in His presence (1 Cor. 1:29, KJV). To a great extent, the thorn will keep us from glorying in His presence. If there were no pain, we would forget; we would lapse into our normal, fleshly routine.
In the same way, the thorn in the flesh keeps us from competing with His glory. It ensures that we will not take any personal credit, and it gives Him all the glory.
In other words, the thorn hurts. It is a constant trial, and it is ever obtrusive. It is always there; it is a reminder. It is a nuisance. Paul even says, " ... to torment me" (2 Cor. 12:7). You may say, "God, that's not very nice." It keeps one's feet on the ground. It keeps me from thinking that I have arrived, that I am good enough, that I am worthy. It hurts so that I might be driven to love more. It is obtrusive so that I might develop empathy and won't be judgmental. Are you, like me, one of those who can hardly keep from pointing the finger? God has a way of sending a thorn in the flesh. It's a nuisance that produces humility.
Excerpted from The Thorn in the Flesh (Charisma House, 2004).