in Bunyan's Pilgrim's Progress, is seized at Vanity
Fair, burnt to death, and taken to heaven in a chariot of fire. A
Puritan used to be called Brother Faithful. The abiding
disciples of any cult are called the faithful.
The hero of Captain Marryat's novel so called. Father of the
faithful. Abraham (Rom. iv.; Gal. iii. 6-9).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894