. >> reporter: becky parker is her name. she was possessed by demons, she formally believes. and she has been saved, she affirms, by the love of god through the rite of exorcism. >> i'm happy because i found god. i found how to win the spiritual battle i was in. >> tell me your name in the name of jesus christ. >> reporter: a spiritual battle. that's what the experience of exorcism feels like to those who go through it. >> speak the truth. speak the truth. >> reporter: and those who perform it. >> i do it because i think it's an incredibly profound opportunity to help in the teaming ministry, that this is fundamentally about. and in a ministry where people are suffering tremendously. >> reporter: father gary thomas is an exorcist, though he did not perform becky parker's exorcism. that priest preferred to remain anonymous. he was trained in rome, and he's been the official exorcist of the diocese of san jose, california. father, is the devil real? >> i do believe the del is real. i've had occurrences and experiences in my life where i believe i've seen the devil. i've seen de