Note 18 at 2 Cor. 12:8: If a person accepts the idea that Paul's thorn was persecution which came from a demonic angel (see note 15 at v. 7, p. 1041), then you might wonder why he would pray three times to have this removed. It is possible that Paul accepted persecution as an inevitable part of the Christian life but he wasn't sure he had to put up with a demonic spirit that incited this persecution. The Lord told him that God's grace would be sufficient and that He would use these persecutions to display His strength in Paul. Once Paul saw this, he actually took pleasure in the persecutions he suffered (v.10), knowing that God would get the ultimate glory.

Note 19 at 2 Cor. 12:8: It is interesting to note that Paul makes special mention of the fact that three times he prayed about this thorn in the flesh. The average Christian today would have no way of knowing how many times he has prayed over situations. Typically, they pray incessantly over the same request. That was not Paul's way of praying. Apparently, praying three times over one thing was unusual for Paul.