2 Corinthians 12:7 (New International Version)

7 or because of these surpassingly great revelations. Therefore, in order to keep me from becoming conceited, I was given a thorn in my flesh, a messenger of Satan, to torment me.


From BibleGateway.com: http://www.biblegateway.com/passage/?search=2 corinthians 12:7&version=NIV