Countless explanations concerning the nature of Paul’s thorn in the flesh have been offered. They range from incessant temptation, dogged opponents, chronic maladies (such as eye problems, malaria, migraine headaches, and epilepsy), to a speech disability. No one can say for sure what Paul’s thorn in the flesh was, but it probably was a physical affliction.
What we do know about this thorn in the flesh comes from Paul himself in 2 Corinthians 7:12 “To keep me from becoming conceited because of these surpassingly great revelations, there was given me a thorn in my flesh, a messenger of Satan, to torment me.” First, the purpose of the thorn in the flesh was to keep Paul humble. Anyone who had encountered Jesus and was spoken to and commissioned by Him (Acts 9:2-8) would, in his natural state, become “puffed up.” Add to that the fact of being moved by the Holy Spirit to write much of the New Testament, and it is easy to see how Paul could become “haughty” (KJV) or “exalted above measure” (NKJV) or “too proud” (NCV). Second, we know that the affliction came from or by a messenger of Satan. Just as God allowed Satan to torment Job (Job 1:1-12), God allowed Satan to torment Paul for God’s own good purposes and always within God’s perfect will.
It is understandable that Paul would consider this thorn a hindrance to wider or more effective ministry (Galatians 5:14-16) and that he would three times petition God for its removal (2 Corinthians 12:8). But Paul learned from this experience the lesson that dominates his writings: divine power is best displayed against the backdrop of human weakness (2 Corinthians 4:7) so that God alone is praised (2 Corinthians 10:17). Rather than removing the problem, God gave him grace and strength through it, and He declared that grace to be “sufficient.”