paying serious attention to religious duties

sincerely believing; devoted

having, showing, sincere devotion to religion

dedicated, religious

neat; formal; (of a person, manner, speech etc) showing dislike of anything rough, rude, improper

particular, fussy

a person who is extremely moral (often exaggerated or affected) in behaviour or speech

prig

making a show (often insincere) of being religious

self-righteous