Christian Universalism, or "Universal Reconciliation," is the view that ultimately every moral being, human and angelic, will be reconciled to God. This does not mean that there is no hell, but only that those who go to hell will be purged and brought to repentance through the fire, and will then be restored to fellowship with God and the saints.
It is a very attractive concept, especially to those who have loved ones who die apart from Christ. Since Christians (like God) love all men, it should be an attractive option in the sight of all Christians, as well as for God Himself, who "desires all men to be saved" (1 Tim.2:4). Surprisingly, there are some Christians, especially Calvinists, who find the view repugnant--apparently because of their belief that God does not love all men and that He does not desire all to be saved.
Of course, the real issue here is not whether the belief in universal reconciliation is pleasant, but whether it is true. Growing up as an evangelical, I always thought of universalism as the view of liberals and Unitarians (which it is, of course), but, until recent years, I never heard of Bible-believing Christians who defended the view.
Universalism was held by Clement of Alexandria, in the second century, and by Origen, in the third. The reputable church Historian, Philip Schaff, has suggested that, at one time, it may have been the predominant view of the ancient church.
Rather than present the arguments for and against universalism here, I would rather direct you to two websites. There is a collection of interesting articles favorable to the doctrine at this site:
http://www.auburn.edu/~allenkc/univart.html. For a rebuttal of the universalist arguments, see:
http://www.carm.org/universalism.htm.
The essential biblical case for universalism rests upon verses like John 12:32/ Romans 11:32/ 1 Corinthians 15:22, 24-28/ 1 Timothy 2:4; 4:10/ Ephesians 1:9-10/ Isaiah 45:23-24/ Phil. 2:10-11; etc.
Theologically, the universalists argue that Christ is everywhere seen as the victor over Satan, and therefore, God must win against His arch-foe in the end. If God wished for all men to be saved, but Satan was able to bring about the eternal damnation of many for whom Christ died (they say), then Satan is the cosmic winner, and God the everlasting loser.
William Barclay (a universalist), put this argument rather powerfully, when he wrote: "If God was no more than a King or Judge, then it would be possible to speak of his triumph, if his enemies were agonizing in hell or were totally and completely obliterated and wiped out. But God is not only King and Judge, God is Father - he is indeed Father more than anything else. No father could be happy while there were members of his family for ever in agony. No father would count it a triumph to obliterate the disobedient members of his family. The only triumph a father can know is to have all his family back home. "
Of course, universalists have their own way of explaining such passages as Matthew 25:46, which speaks of "everlasting punishment," and not every biblical student will find these explanations convincing. One serious defect in the doctrine would seem to be Jesus' comment that those who blaspheme the Holy Spirit will not be forgiven "either in this age or in the age to come" (Matt.12:32).
You can see that I am not as alarmed by universalism as are some evangelicals. Frankly, I find there to be credible biblical cases to be made for various views of the fate of the wicked, whether eternal torment. conditional immortality (annihilationism), or universal reconciliation. To say that there are "credible biblical cases" for these views does not mean that any of them has an air-tight case in scripture, or that biblical arguments cannot be raised against each of them. I believe the ambiguity of scripture on this point is deliberate.
The Bible is not written for non-Christians. It is the covenant document for the church. It is not necessary for those who are saved to know the exact future disposition of those who die lost. Nor is God obliged to give the whole story to those who are lost, so that they might "weigh their options." It seems to me that the possibility of eternal torment or of annihilation looms as a credible, possible threat to those who presume to reject the grace of God in this life, so that they can have no comfort or security in their rebellion. Even if universaism proved to be correct, it does not eliminate the prospect of a hell of proportionate punishment for those who die hating God.
On the other hand, those verses that give rise to a universalist hope allow us to consider at least the possibility that Christ will eventually be able to present to His Father all that He paid for, and that our eternity may prove to be one of unmixed rejoicing. If I sound too wishy-washy on this point, I apologize. I have studied too much to be overly sure of myself.