Verses 15-20 comprise a set of examples that illustrate the way the community could discern the false prophets noted in verse 15. The entire set depends upon the problem of detecting false prophets, and therefore becomes a prediction that such false prophets would arise, else there would be no reason to attempt to discern them. Certainly this information is completely appropriate for the Old World where the apostasy was a predicted result of the incipient Christian gospel. That gospel would begin, but it would also end. There would be the apostles and others such as Paul who preached the gospel, but there were many others who formally or informally preached something different. Indeed, we need go no farther than Paul’s letters to see that the communities he established moved away from correct teachings not long after he had established the true gospel among them.
The first hundred years after the death of Christ saw an explosion of Christianity, but it also saw tremendous pressures on Christian communities, and situations that differed greatly from the earliest Christian communities. The Didache is a church manual from perhaps 110 AD, and it describes a community of believers who accepted itinerant teachers, preachers, apostles, and prophets as they came through. Among these were also the good and the bad, and that document contains many of its own hints on how to tell the true from the false.
The ultimate proof of the true nature of a person is expressed in a botanical metaphor. The relationship between plant and fruit is used to show that the visible result is a witness to the invisible essence. Thus it is impossible to gather “grapes of thorns, or figs of thistles.” We can only receive fruit from the plant where the essence of the plant is to produce such a fruit. In this case, we can have good fruit only from a good plant.
There are, of course, plants that ought to be good that still do not produce good fruit. We do not expect figs grapes of thorns, but we do expect grapes of a grape vine. Nevertheless, there may be some grape vines that still do not produce good fruit. The entire olive allegory in Jacob depends upon the fact that some fruit is not good, regardless of the type of tree. The imagery therefore, insists that the visible results are the best indicator of the invisible intent.
Book of Mormon Context As with the sayings on the roads, this saying would have been of limited usefulness in the Nephite community. Although there had been some experiences with false prophets in the Nephite history, such as Nehor and Korihor, this was not the typical experience. Particularly for the next two hundred years there would be not similar situation to Old World. Just as the Nephites were dominant rather than a minority as the Christians of the Old World were, the Nephites also were able to control the gospel rather than suffer through the types of widespread apostasy that were part of the Old World situation. These sayings might have had some relevance when the Nephite decline began after two hundred years, but they certainly lacked the immediacy of the Old World context.
Textual: There are no changes from the Matthean text.