The scriptures warn us that in the last days there will be prophets who do not prophesy and seers who do not see (Isaiah 30:10). Jesus also warned that there would be false prophets and an abundance of men teaching their own precepts to get gain, so that even the very elect will be deceived (2 Nephi 26:29; JS Matthew 1:22).
As Latter-day Saints we must learn what a true prophet is and we must learn to discern between true and false prophets lest we also be deceived.
The scriptures provide a standard by which we can all judge. Simply put, a prophet must have the spirit of prophecy in order to be a true prophet. This is the sign.
As we watch General Conference we should look for the spirit of prophecy. We should measure carefully what is being said. We should pray that those who we sustain as prophets will prophesy and speak prophetically because when prophets and seers, prophesy and see, they become a great benefit to their fellow man (Mosiah 8:18). This is the means whereby we can receive salvation.
If men who are called prophets do not have the spirit of prophecy we can know they are false prophets. Nephi gives us an important bar by which we can measure:
Wherefore, hearken, O my people, which are of the house of Israel, and give ear unto my words; for because the words of Isaiah are not plain unto you, nevertheless they are plain unto all those that are filled with the spirit of prophecy (2 Nephi 25:4).
All prophets will understand the words of Isaiah. They will also share the testimony of the Savior and of Nephi and others that the words of Isaiah are great! (3 Nephi 23:1).
When’s the last time you heard an LDS prophet give a talk on the words of Isaiah in General Conference? When Jesus came to the Nephites, He gave them the “commandment to search these things diligently; for great are the words of Isaiah.” Do the servants of the Lord today emphasize this same commandment?
In a cursory search on DeseretBook.com, I found 21 books on the topic of Isaiah: