The reader pointed out a supposed inconsistency in LDS doctrine, because Joseph Smith taught that matter is eternal, which would seem to indicate a steady state universe.
I pointed out that this does not mean that the Church supports the steady state theory. After all, Joseph Smith taught that "Spirit" was a type of matter, and Spirit is eternal. Therefore, he was not necessarily referring to the physical universe.
There are other issues, such as the mysterious nature of the Singularity, which leave Joseph Smith's comments rather ambiguous. Ultimately, the church has no official position on how the Creation happened, and it allows its members to believe what best makes sense to them.
However, I recently came across this quote by the second President of the Church, Brigham Young:
In these respects we differ from the Christian world, for our religion will not clash with or contradict the facts of science in any particular...whether the Lord found the earth empty and void, whether he made it out of nothing or out of the rude elements; or whether he made it in six days or in as many millions of years, is and will remain a matter of speculation in the minds of men unless he give revelation on the subject. If we understood the process of creation there would be no mystery about it, it would be all reasonable and plain, for there is no mystery except to the ignorant.
—Brigham Young, (May 14, 1871) Journal of Discourses 14:116.
The context of this quote is Brigham Young commenting on the relationship between science and religion. The religionists of the day pushed the idea that God "made the earth out of nothing in six days, six thousand years ago."
Brigham Young says that in these respects we differ from Christians because, as I explained to this reader, we do not make this claim. We do not know exactly how the Creation happened, but "our religion will not clash with or contradict the facts of science in any particular."
Whatever science says, we agree.