church vs church service

church and church service both are nouns.

Word	Noun	Adjective	Verb	Adverb
church	Yes	No	Yes	No
church service	Yes	No	No	No

As nouns, church and church service are synonyms defined as:

church (noun)	church service (noun)
a service conducted in a house of worship	a service conducted in a house of worship
a place for public (especially Christian) worship
one of the groups of Christians who have their own beliefs and forms of worship
the body of people who attend or belong to a particular local church

church (verb)	church service (verb)
perform a special church rite or service for