And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure.
(2 Cor. 12:3-7)

Let's approach this subject from another angle. There are several Scriptures in the Bible that refer to thorns in the side or in the eye and none of these Scriptures indicate sickness. It is just a figure of speech.

You have heard people say, "So-and-so is just a pain in the neck." Well, he isn't really a pain in the neck. That's just a figure of speech. That means he gives you trouble.

People Are the Thorns, Not Sickness
Let's look at Numbers 33, where God is speaking to the children of Israel:

But if ye will not drive out the inhabitants of the land from before you; then it shall come to pass, that those which ye let remain of them shall be pricks in you eyes, and thorns in your sides, and shall vex you in the land wherein ye dwell.
(Num. 33:55)

Pricks in your eyes, and thorns in your side. Here, you can see He is talking about people. He is not talking about sickness. The people that you don't cast out of the land will become thorns in your side. This is only a figure of speech.

Look now at Joshua 23:

Know for a certainty that the Lord your God will no more drive out any of these nations from before you; but they shall be snares and traps unto you, and scourges in your sides, and thorns in your eyes, until ye perish from off this good land which the Lord your God hath given you.
(Josh. 23:13)

God is telling them, "If you don't drive them out, they will become thorns in your eyes." Here again it is a figure of speech.

In Judges 2, we also have a reference to a thorn, yet in none of these instances does the Word indicate sickness or disease.

And ye shall make no league with the inhabitants of this land; ye shall throw down their altars: but ye have not obeyed my voice: why have ye done this?

Wherefore I also said, I will not drive them out from before you; but they shall be as thorns in your sides, and their gods shall be a snare unto you.
(Judg, 2:2-3)

Here again you can see it is used in reference to people. They will become thorns in your sides. So we see that when the Scriptures refer to a thorn in the flesh it never once refers to sickness. There is no scriptural basis for the belief that Paul was referring to any kind of sickness.

Source: The Messenger Of Satan by Charles Capps.
Excerpt permission granted by Harrison House Publishers