In the book of Joel there are only scanty allusions to Phoenicians, Philistines, Egypt and Edom, couched in terms applicable to very different ages, while the prophet's own people are exhorted to repentance without specific reference to any of those national sins of which other prophets speak.
Its starting-point was a dispute with Melanchthon in 1527 as to the relation between repentance and faith.
Agricola gave the initial place to faith, maintaining that repentance is the work, not of law, but of the gospel-given knowledge of the love of God.
Its object, like other Jewish apocalypses, was to encourage faith under persecution; its burden is not a call to repentance but a promise of deliverance.
But as he does so, it is added to, in the way of detail and illustration, by a fresh series of revelations through an angel in the guise of a Shepherd, who in a preliminary interview announces himselt as the Angel of Repentance, sent to administer the special " repentance " which it was Hermas's mission to declare.