Father Clarke is a minor character mentioned in FAITH: Chapter II and its demo.
Father Clarke was the acting priest for the Snake Meadow Hill Church. In his lifetime as a priest for the church, he experienced first hand many of the tragedies surrounding the church. These included the deaths of six orphan children and the multiple disappearances of staff. Father Clarke quickly befriended an investigator sent out to investigate the missing people. They would often take evening car rides along the secluded roads surrounding Snake Meadow Hill Church in search of the missing people. On one fateful evening, Father Clarke and the investigator were woken from their sleep by a loud, older woman's cackling. Storming into the church to discover the source, they both observed what looked like the deceased nun Sister Miriam Bell dragging the last remaining orphans of the church, two twin boys, into the church's basement. As the investigator prepared to engage Miriam Bell with his service weapon, Father Clarke stopped him and stated that it was "God's work" now. He descended into the dark basement, sealing the door to ensure neither he nor whatever lurked in the basement could escape.
John Ward comes across the last written testament of Father Clarke at the entrance to the church's basement. It is fittingly scrawled on a torn piece of paper from The Bible. In it, Clarke fully accepts that he may very well meet his end in engaging whatever lurks below the basement. He notes that the demon has been screaming, resulting in his ears bleeding, and that the demonic presence has caused his mental sanity to drain. Even time does not move forward, he claims. He begs for God to help him in his hour of need and is presumably killed. Whether this is Father Clarke's real demise is left for speculation, as it is revealed at the end of FAITH: Chapter II that everything John Ward experienced was a nightmare.