Complex sentence: At first, the church folks do not believe Tom, Lance, and Mrs. Banks, but are quickly convinced when one of the churchgoers goes outside and they hear him screaming as he is slowly killed.
Split into simpler sentences: At first, the church folks do not believe Tom, Lance, and Mrs. Banks. They quickly believe the trio's words when one of the churchgoers leaves church and they hear him screaming outside as he is slowly killed.