+ In memoriam Iohannis Gerhardi, uiri summae pietatis atque doctrinae. +
The fathers were fairly profuse in their allegories, while some today are fairly hostile to them. So what should be decided about allegories?
Gerhard warns that it is very easy to stray from the rule of faith when allegorizing (we're looking at you, Origen). He navigates the proper use of allegory in a few ways. He starts by noting the rhetorical distinction between a type and an allegory. What Paul is doing in Gal. 4:24, for example, is actually typology though he uses the term "allegory." Likewise, the fathers sometimes misuse these terms.
When used appropriately and sparingly, allegories delight, stimulate, and remove tedium, which is why they are especially well suited for sermon openings [exordiis]. One must work tirelessly to make allegories appropriate, firstly and foremost that they be analogous to the faith.
This must be why Gerhard always starts his sermons with a type or allegory from the OT that pertains to the Sunday Gospel.
Be sure, however, not to search too far for allegories, for then they will be crude and inane. Be sure they do not militate against the chief parts of the historical account that we want to treat allegorically. Do not dwell on them longer than they deserve; instead, approach them gracefully, simply touching upon them with a few words subtly and discreetly. Let them not be too intricate or perplexing. In short, it is not for everyone to appropriately and fittingly use allegories. Those who are less practiced in them should proceed soberly and prudently. Those who make use of allegories hastily and without discernment can easily propose something that the learned will contemn, the vicious will mock, and that will cause the weak to stumble. Undoubtedly Origen was rebuked by the ancients on this charge.