“It is appointed for men to die once, and after that comes judgment” (Heb. 9:27). There are no “second chances” after death. Consequently, God judges individuals based on their actions in this life. Since he is a just judge, he does not hold people accountable for what they did not and could not have known.
There is no other evidence in the Bible or in the early Church Fathers’ writings of baptism being practiced on the living in place of the dead. Some Mormon writers assert that some Christian commentators have discussed the possibility of a kind of “baptism for the dead” among some in the Corinthian community in Paul’s time. But these commentators do not suggest that the practice was accepted or mainstream. Given the silence of Scripture and tradition, we conclude rightly when we see this behavior as another aberration within a community of believers already soundly scolded by Paul for its lack of charity, its factionalism, its immorality, its abuse of the Eucharist, and other matters.
Although we have no way of knowing for sure who was engaging in this practice, it is certain that Paul was not referring to orthodox Christians baptizing the dead. Catholic and Protestant scholars agree on that.
The case against baptism for the dead is also made by the Mormon scriptures themselves. The current Mormon doctrine on baptism for the dead is quite unlike what Joseph Smith first taught. As in other cases, the Book of Mormon becomes an important tool for the Christian apologist. It contradicts much Mormon theology, and baptism for the dead is no exception.
In Alma 34:35-36 we read: “For behold, if ye have procrastinated the day of your repentance even until death, behold ye have become subjected to the spirit of the devil, and he does seal you his. Therefore, the spirit of the Lord has withdrawn from you and hath no place in you; the power of the devil is over you, and this is the final state of the wicked.”
In other words, those who die as non-Mormons go to hell, period. There’s no suggestion of a later, vicarious admission into the Mormon church.
We also see present-day Mormon doctrine contradicted in 2 Nephi 9:15: “And it shall come to pass that when all men shall have passed from this first death unto life, insomuch as they have become immortal, they must appear before the judgment seat of the Holy One of Israel, and then cometh the judgment and then must they be judged according to the holy judgment of God. For the Lord God hath spoken it, and it is his eternal word, which cannot pass away, that they who are righteous shall be righteous still, and they who are filthy shall be filthy still; wherefore, they who are filthy . . . shall go away into everlasting fire, prepared for them; and their torment is as a lake of fire and brimstone, whose flame ascendeth up forever and ever and has no end.”
It is unforunate that Smith abandoned his own, earlier doctrine. It would not have made the Mormon scriptures any more authentic, but it would have prevented millions of futile Mormon proxy baptisms from being performed.
Catholic Answers