The Only Use of

gospel
in
To Kill a Mockingbird

My confidence in pulpit Gospel lessened at the vision of Miss Maudie stewing forever in various Protestant hells.
p. 49.9

gospel = religious teachings

Definitions:

(1) (gospel as in: gospel of the Bible)
the religious teachings of Jesus

or:

one of the four books in the New Testament (Matthew, Mark, Luke, and John) that Christian's believe tell the story of Jesus Christ's life and teachings
(2) (gospel as in: they consider it gospel)
a set of beliefs firmly held by a group

or:

an unquestionable truth
(3) (gospel as in: gospel music)
a type of vocal music that originated in African-American churches in the United States