Mormons say Smith's Prophecy about the Second Coming was not False

Joseph Smith prophesied that Jesus would return no later than 1891 (see False Prophecies of Joseph Smith for the details). I consider this to be a false prophecy.

Mormons have responded to this by quoting another Mormon document which alters the original prophecy given by Smith.

The apparent attempt to cover up this false prophecy is in Doctrine and Covenants 130:14. In 1843, Smith went back and told a different story about the revelation God had suppsedly given him. This time, Smith claimed God said that if Smith lived to be 85, he would get to see Jesus' face. Smith said he didn't know if God was talking about the Second Coming, an appearance of Jesus to Smith before the Second Coming, or Smith dying when he turned 85 to see Jesus then. Smith then claims, "I believe the coming of the Son of Man will not be any sooner than that time."

Smith made this ambiguous correction 8 years after he originally said Christ would return no later than 1891. This time, Smith says Jesus would not return before 1891, that he's not even sure if it's about Jesus' return, and that it's all conditional on whether Smith lives to be 85. Of course, this doesn't even make sense, since we're told that Smith received his revelation in response to praying to God about the timing of the Second Coming. That is, the supposed revelation was clearly about the timing of the Second Coming.

Essentially, Smith changed his story. He went back 8 years later to change something he said, trying to make it so ambiguous that it could not possibly be disproved. Whichever claim you accept as accurate - the original or the attempted cover-up (which, as pointed out, doesn't make sense since the revelation was clearly about the Second Coming) - Smith contradicted himself. Besides that, Smith's "prophecy" (in it's newer incarnation) became entirely useless. Anyone anywhere could make the same claim that Smith made the second time - that Christ will not return before such-and-such a date - and call it a prophecy. Just like Smith, they're safe either way. If Christ returns, then the kingdom begins and the false prophecy doesn't matter. If, as is more likely, Christ doesn't return, then the self-proclaimed prophet could claim to be a prophet just as Smith did.

As a final note, Smith made his prophecy very clear, in his own words, in a diary entry made in 1843:

I prophecy is the name of the Lord God, and let it be written, that the Son of Man will not come in the heavens till I am 85 years old, 48 years hence or about 1890.Joseph Smith, April 6, 1843

Smith tried to cover his prophecy up and make it ambiguous. Liars have always had problems staying consistent.