12:7 thorn in the flesh. This “thorn in the flesh” was not some spiritual burden, but a physical ailment to keep Paul continually aware that, despite the abundance of spiritual privileges given him, he was painfully human. The exact nature of this physical problem is unknown, though there have been numerous conjectures. Actually, it is best that it remain unknown, so that Christians of all times and places (each of whom has some “thorn in the flesh,” which God has not been pleased to remove) can better learn to know and appreciate the sufficient grace of God which enables them to continue serving Him despite the pain, and which encourages them to look all the more toward His coming at that day when “there shall be no more death, neither sorrow, nor crying,” and not even “any more pain!” (Revelation 21:4).
12:7 messenger. “Messenger” is the same word as “angel.” Satan, being a created being, is not omnipresent, but he has a multitude of fallen angels, or evil spirits, that do his evil work among men. In Job’s case (Job 2:4-6) and here in Paul’s case, God allowed these creatures to vent their hatred against God’s people in inflicting them with physical afflictions, hoping thereby to cause them to rebel against God or to destroy their testimony in some way. It would be unwise, of course, to blame all pain and sickness on Satan, except in the general sense that he introduced sin and its consequences into God’s perfect creation. Nevertheless, this particular cause of pain is always a possibility that should at least be considered, and perhaps dealt with accordingly.
12:8 besought the Lord thrice. Although Paul’s prayers and spiritual gifts had brought physical healing to many others, he could not heal himself. While God is often pleased to answer prayers for healing, it must always depend upon the will and purpose of God for the individual. In God’s infinite wisdom and in the light of eternity, it may be best in many cases not to heal, and we must be content, if that is so.
12:9 glory in my infirmities. We need to learn to thank God, rather than complain to God and others, about our “infirmities,” reproaches, “necessities,” “persecutions,” “distresses for Christ’s sake” (II Corinthians 12:10). God’s strength, paradoxically, is not measured in ordinary human terms (e.g., riches, physical prowess, beauty, intellect), but rather “is made perfect in weakness.”