gospel vs gospel truth

gospel and gospel truth both are nouns.

Word	Noun	Adjective	Verb	Adverb
gospel	Yes	No	No	No
gospel truth	Yes	No	No	No

As nouns, gospel and gospel truth are synonyms defined as:

gospel (noun)	gospel truth (noun)
a doctrine that is believed to be of great importance	an unquestionable truth
the written body of teachings of a religious group that are generally accepted by that group
an unquestionable truth
folk music consisting of a genre of a cappella music originating with Black slaves in the United States and featuring call and response; influential on the development of other genres of popular music (especially soul)