The apostle Paul describes being tormented by a "messenger of Satan":

2 Corinthians 12:7: “Because of the surpassing greatness of the revelations, for this reason, to keep me from exalting myself, there was given me a thorn in the flesh, a messenger of Satan to torment me – to keep me from exalting myself!” [NAS]

Some of the theories suggested for the source of Paul's torment include:

  • Temptation,
  • Chronic eye problems,
  • Malaria,
  • Migraines,
  • Epilepsy, and,
  • Someone (such as Alexander the coppersmith, 2 Tim. 4:14).

Of course, there are other reasons cited, but I'm unconvinced that this has been satisfactorily addressed from a spiritual perspective. Of course, it may never be revealed in this life, but I believe it's worthy of further pursuit.