A couple years ago while participating on a maillist of scientists who were Christians, I read the following from a sincere and intelligent Christian who was troubled over the issue of salvation for those who never had the chance to learn of Christ:
It is a stunning, and somewhat depressing, fact that if our understanding of demographics and history are correct, the vast majority of human beings who are living or who have lived are not Christian. Furthermore, among those who are living, a majority will die not being a Christian. This implies that the destiny of most of the human race is Hell.
Consider the Chinese rice farmer, the Indian beggar, the Russian mobster, the Pakistani Moslem priest, or the French intellectual: each will go through life in a different way–some in misery, others in luxury but each with their own unique loves, joys, aspirations, fears, desires, triumphs and failures. And yet their future is the same: an eternity of unimaginable terror. All of human history with its complexity, texture, drama, mystery, and vice is to be sent through a sieve to produce an elegant, bipolar universe of rapture and horror that defies comprehension.
How grateful I am for the restoration of divine truth about the justice and mercy of God, and the restoration of the authentic ancient Christian and modern Mormon practice of baptism for the dead.
In my reply, I referred to God’s love and justice, and his desire to “have all men to be saved, and to come unto the knowledge of the truth.” (1 Tim. 2:4) I then introduced the scriptures in Peter that refer to preaching of the Gospel to the dead (1 Peter 3:18,19 and 1 Peter 4:6), and then referred to baptism for the dead. What a beautiful doctrine!
At the time of Joseph Smith, about the only hint at this ancient practice was in 1 Cor. 15:29, which doesn’t explain much. But we now know from numerous other sources that at least some early Christians did practice vicarious baptisms for those who had died. LDS scholars are not the only ones who recognize this!
The actual performance of baptisms for the dead in the Temple is also a spiritual and uplifting time, one that many LDS people cherish when they have the opportunity to do this. It’s a wonderful youth activity, especially if the kids are properly prepared.