At times God allows certain saints to receive what is know as the stigmata, the miraculous presence of Jesus’ wounds reproduced in the body.
The wounds usually appear visibly on the head (as Jesus' head was wounded by the crown of thorns), on the hands and feet (as Jesus was wounded with the nails), and on the side (as Jesus was wounded with the lance).
But some saints have borne the stigmata invisibly, with the wounds causing pain but not being visible to the outside world.
St. Faustina falls into this last category, as she did not have any external wounds, but only invisible wounds that produced an intense amount of pain.
Invisible stigmata
St. Faustina explains her experience in her Diary:
When I experienced these sufferings for the first time, it was like this: after the annual vows, on a certain day, during prayer, I saw a great brilliance and, issuing from the brilliance, rays which completely enveloped me. Then suddenly, I felt a terrible pain in my hands, my feet and my side and the thorns of the crown of thorns. I experienced these sufferings during holy Mass on Friday, but this was only for a brief moment. This was repeated for several Fridays. (Diary, 759)
For St. Faustina, this was an occasional pain, one that only lasted for a short amount of time. Some saints experienced the pain more frequently, while others simply had the external sign, with little pain.
God does not grant such a grace for no particular reason, but typically to invite an individual into his pain and suffering, and to help that saint offer the pain for others.
St. Faustina saw the pain as a way that she could offer suffering for the conversion of souls:
During holy Mass one Friday, I felt myself pierced by the same sufferings, and this has been repeated on every Friday and sometimes when I meet a soul that is not in the state of grace. Although this is infrequent, and the suffering lasts a very short time, still it is terrible, and I would not be able to bear it without a special grace from God. There is no outward indication of these sufferings. What will come later, I do not know. All this, for the sake of souls. (Diary, 759)
St. Faustina received many special graces in her life, graces that she didn't ask for, but that were granted to her because of her receptivity and openness to God's will.
