Christadelphian apologist, Duncan Heaster, on this Website, wrote the following:
The Mormons have a really twisted doctrine about baptism for the dead which they base on a single passage in Paul's first letter to the Corinthians (I Corinthians 15:29) which appears to teach it. (source)
Firstly, a good exegetical case can be made in favour of the Latter-day Saint understanding of posthumous salvation from 1 Cor 15:29, as well as 1 Pet 3:18-20; 4:6. For a discussion on 1 Cor 15:29, see my blog post here, for instance. As a Christadelphian, Heaster's dismissal of the LDS practice is not grounded in exegesis, per se, but his acceptance of soul-death (thnetopsychism), so baptism for the dead is, at best, a superfluous practice. Furthermore, LDS base our practice, not on 1 Cor 15:29 per se, but the same (ultimate) source of 1 Cor 15:29—divine revelation from God to an oracle (in this case, the revelations of the Prophet Joseph Smith). Even if there was no biblical text for the doctrine, that would not be an issue for Latter-day Saints, as we don’t hold to the false practice/notion of sola scriptura.
However, I wish to use Heaster's comment to show that "Mormonism," unlike Protestantism and other groups that hold to some formulation of sola scriptura, is not bound to Scripture (not just the Bible [click here to see posts refuting sola scriptura]), and do not hold to any singular authority as being infallible/inerrant/impeccable. Consider the following quotations from LDS leaders (examples could be multiplied):
When God speaks to the people, he does it in a manner to suit their circumstances and capacities. He spoke to the children of Jacob through Moses, as a blind, stiff-necked people, and when Jesus and his Apostles came they talked with the Jews as a benighted, wicked, selfish people. They would not receive the Gospel, though presented to them by the Son of God in all its righteousness, beauty and glory. Should the Lord Almighty send an angel to re-write the Bible, it would in many places be very different from what it now is. And I will even venture to say that if the Book of Mormon were now to be re-written, in many instances it would materially differ from the present translation. According as people are willing to receive the things of God, so the heavens send forth their blessings. If the people are stiff-necked, the Lord can tell them but little.
Brigham Young, Journal of Discourses 9:311
Were the former and Latter-day Saints, with their Apostles, Prophets Seers, and Revelators collected together to discuss this matter [the nature of Deity], I am led to think there would be found a great variety in their views and feelings upon this subject, without direct revelation from the Lord. It is as much my right to differ from other men, as it is theirs to differ from me, in points of doctrine and principle, when our minds cannot at once arrive at the same conclusion.
-Brigham Young, Journal of Discourses, 2:123
…we believe, from the Scriptures of truth, that to every church in the past ages, which the Lord recognized to be his, he gave revelations wisely calculated to govern them in the peculiar situation and circumstances under which they were placed, and to enable them by authority to do the peculiar work which they were to perform. The Bible contains revelations given at different times to different people, under different circumstances, as will be seen by editorial articles in this paper. The old world was destroyed for rejecting the revelations of God, given to them through Noah. The Israelites were destroyed in the wilderness for despising the revelations given to them through Moses; and Christ said that the world, in the days of the apostles, should be condemned for not receiving the word of god through them: thus we see that the judgments of God in the past ages have come upon the people, not so much for neglecting the revelations given to their forefathers, as for rejecting those given immediately to themselves. Of the blessings of heaven it may be said, they have always rested upon the heads of those to whom they were promised: Therefore, seeing that it not only was, but as long as God remains the same, always will be the privilege of the true church to receive revelations, containing blessings and cursings, peculiarly adapted to itself as a church.
-The Evening and the Morning Star- July 1832, 13.
God said, "Thou shalt not kill;" at another time He said, "Thou shalt utterly destroy." This is the principle on which the government of heaven is conducted-by revelation adapted to the circumstances in which the children of the kingdom are placed. Whatever God requires is right, no matter what it is, although we may not see the reason thereof till long after the events transpire.
-Teachings of the Prophet Joseph Smith, 256.
Brother Brigham took the stand, and he took the Bible, and laid it down; he took the Book of Mormon, and laid it down; and he took the Book of Doctrine and Covenants, and laid it down before him, and he said: "There is the written word of God to us, concerning the work of God from the beginning of the world, almost, to our day." "And now," said he, "when compared with the living oracles those books are nothing to me; those books do not convey the word of God direct to us now, as do the words of a Prophet or a man bearing the Holy Priesthood in our day and generation. I would rather have the living oracles than all the writing in the books." That was the course he pursued. When he was through, Brother Joseph said to the congregation, "Brother Brigham has told you the word of the Lord, and he has told you the truth."
- President Wilford Woodruff, Conference Report, October 1897, pp. 22-23.
The Latter-day Saints do not do things because they happen to be printed in a book. They do not do things because God told the Jews to do them; nor do they do or leave undone anything because of the instructions that Christ gave to the Nephites. Whatever is done by this Church is because God, speaking from heaven in our day, has commanded this Church to do it. No book presides over this Church, and no book lies at its foundation. You cannot pile up books enough to take the place of God's priesthood, inspired by the power of the Holy Ghost. That is the constitution of the Church of Christ. … Divine revelation adapts itself to the circumstances and conditions of men, and change upon change ensues as God's progressive work goes on to its destiny. There is no book big enough or good enough to preside over this Church.
-Elder Orson F. Whitney, Conference Report, October 1916, p. 55. Quoted by Loren C. Dunn, in General Conference, Ensign May 1976, p.65-66
"We who have been called to lead the Church are ordinary men and women with ordinary capacities,"
-Boyd K. Packer, "Revelation in a Changing World," Ensign (November 1989): 16.
"We make no claim of infallibility or perfection in the prophets, seers, and revelators."
-James E. Faust, "Continuous Revelation," Ensign (November 1989): 11.
"I am not a perfect man, and infallibility does not come with the call [of Apostlehood]."
-Robert D Hales, Ensign, May (1994):78
"the President is not infallible. He makes no claims to infallibility. But when in his official capacity he teaches and advises the members of the Church relative to their duties, let no man who wants to please the Lord say aught against the counsels of the President."
-Alma P. Burton, Ensign, Ensign, October (1972):6.
Though general authorities are authorities in the sense of having power to administer Church affairs, they may or may not be authorities in the sense of doctrinal knowledge, the intricacies of church procedures, or the receipt of the promptings of the Spirit. A call to an administrative position itself adds little knowledge or power of discernment to an individual.
-Elder McConkie, Mormon Doctrine, "General Authority"
With all their inspiration and greatness, prophets are yet mortal men with imperfections common to mankind in general. They have their opinions and prejudices and are left to work out their problems without inspiration in many instances.
-Elder McConkie, Mormon Doctrine, "Prophets"
-Boyd K. Packer, "Revelation in a Changing World," Ensign (November 1989): 16.
"We make no claim of infallibility or perfection in the prophets, seers, and revelators."
-James E. Faust, "Continuous Revelation," Ensign (November 1989): 11.
"I am not a perfect man, and infallibility does not come with the call [of Apostlehood]."
-Robert D Hales, Ensign, May (1994):78
"the President is not infallible. He makes no claims to infallibility. But when in his official capacity he teaches and advises the members of the Church relative to their duties, let no man who wants to please the Lord say aught against the counsels of the President."
-Alma P. Burton, Ensign, Ensign, October (1972):6.
Though general authorities are authorities in the sense of having power to administer Church affairs, they may or may not be authorities in the sense of doctrinal knowledge, the intricacies of church procedures, or the receipt of the promptings of the Spirit. A call to an administrative position itself adds little knowledge or power of discernment to an individual.
-Elder McConkie, Mormon Doctrine, "General Authority"
With all their inspiration and greatness, prophets are yet mortal men with imperfections common to mankind in general. They have their opinions and prejudices and are left to work out their problems without inspiration in many instances.
-Elder McConkie, Mormon Doctrine, "Prophets"
