Church appears to be a type V construction with the lower basement level ceiling made of steel and concrete. I'm not sure if this qualifies as non-rated.
Art 334 (3) permits its use in structures type III, IV, V. unless prohibited by 334.12 (churches not specifically mentioned).
Art. 518 does refer to assembly occupancies and refers to art. 518.4 wiring methods part B non-rated construction. This section leads me to believe the structure would qualify as non-rated and permit the use of NM cable. ??