By now, to state that Rob Bell is a hell-denying universalist is almost a moot point. How ever he tries to evade the label by a well-crafted blend of ambiguous speech and smirking, it really just sticks.
But it must be noticed that there are actually two basic kinds of universalism. The first, "in its simplest form...claims that everyone goes to heaven immediately after death, regardless of what they have believed or how they have behaved; regardless, even, of whether they were religious or irreligious. R.C. Sproul summarizes this position: 'A prevailing notion is that all we have to do to enter the kingdom of God is to die. God is viewed as being so 'loving' that he really doesn't care too much if we don't keep his law. The law is there to guide us, but if we stumble and fall, our celestial grandfather will merely wink and say, 'Boys will be boys''." 
Bell's position is of the second sort:
"The second form of universalism is what J.I. Packer criticized when he wrote, 'For universalists, hell is never the ultimate state: It is, rather, a stage in the journey home.' One of the earliest church leaders to formalize this theory was the Egyptian theologian Origenes Adamantius (c.185-c.254). Origen, as he has come to be known, was a man of great determination and personal discipline; he even castrated himself to avoid certain sexual temptations. He was a prolific writer, a famous preacher and a persuasive teacher, but his theology was a hotchpotch of truth and error. It used to be said, 'Where Origen was good, no one was better; where he was bad, no one was worse.'
Among his most controversial ideas were those relating to man's origin and destiny. With a great deal of Greek philosophy mixed into his thinking, he taught that God created a host of intellectual beings, almost all of whom he later rejected because of some unspecified sin. The least guilty became angels, the worst culprits devils, and the rest human beings. Our bodies are therefore a punishment for sin, but by the exercise of free will we can work our way back into God's favour. Our punishment and correction will continue after death, but eventually purification will be complete, God will be satisfied and we shall be restored to fellowship with him. However, this restoration, or universalism, is not limited to human beings; every fallen angel, every evil spirit, and even the devil himself will eventually be reconciled to God.
These unorthodox views got Origen into serious trouble and his teaching was so decisively disowned by the church's ruling authorities that at the second Council of Constantinople, held in A.D. 553, he was listed among 'ancient heretics', and for something like 1,500 years after Origen's death universalism received little or no serious support. Surely these are pretty significant facts!
Towards the end of the eighteenth century John Murray, an excommunicated Methodist preacher, left Ireland for America and began to spread the doctrine of universalism in New England, eventually being instrumental in founding the first Universalist Church. Although many other doctrines taught by Murray were biblically sound, his successors gradually abandoned these and under the influence of men like Hosea Ballou (1771 - 1852) the Universalist Church threw out the doctrines of the Trinity, the deity of Christ, original sin and the need for conversion. Within 100 years the church had almost no doctrinal moorings and welcomed 'all humane men' into its membership. In 1961 it merged with the equally unbiblical Unitarians to form the Unitarian-Universalist Association.
In Europe, the German theologian Friedrich Schleiermacher (1768 - 1834), who denied the deity of Christ and the necessity of the Virgin Birth, gave universalism a powerful boost by teaching that God had decreed the universal restoration of all souls. A century later this impetus was given another shot in the arm by the Swiss theologian Karl Barth (1886 - 1968), who believed that although the Bible's writers claimed to have written the Word of God, they could 'never sustain that claim' and that there were times when they were 'actually guilty of error in their spoken and written word'. Barth taught that all humanity's destiny is fulfilled in Christ, and he reached the very brink of universalism by doubting that God could finally condemn anyone. He publicly denied that he was a universalist—even though he taught that 'We are already in [God's] kingdom...we already belong to it'—but his massive reputation made it easy for others to embrace the full-blown doctrine.
Barth's contemporary and fellow-countryman Emil Brunner (1889 - 1966), who wrote that 'The Bible is full of errors, contradictions, erroneous opinions concerning all kinds of human, natural, historical situations,' was another influential scholar who took a universalist line. He said that 'The doctrine of forgiving grace...finds its crown in a proclamation of universal redemption.'
Nels Ferré, (1908 - 1971), put it more simply: 'God has no permanent problem children'; in other words, after death God will keep the pressure on until even the most rebellious sinner gives in and acknowledges God as his Father. Elsewhere Ferré wrote that 'The final victory of final love is universal salvation' and that Christianity's message is 'deceit except it end in a hallelujah chorus'.
The liberal British minister C.H. Dodd (1884 - 1973) taught that God would eventually forgive everyone and treat unbelievers as if they had believed. Elsewhere, he wrote that 'In the end no member of the human race is left outside the scope of salvation.'
The Scottish theologian William Barclay, another liberal, took the same line. He said that although God was both King and Judge he was also Father—'indeed, Father more than anything else'. From that base, Barclay argued that 'No father could be happy while there were members of his family 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.'...Barclay's case collapses even before we get to them, because he bases it on the assumption that God is the Father of all humanity, whereas Jesus told his enemies, 'You belong to your father, the devil' (John 8:44). In terms of salvation, the idea of the universal fatherhood of God and brotherhood of man is nothing more than a convenient catch-phrase; the Bible makes it clear that the only way to become 'sons of God' is 'through faith in Christ Jesus' (Galatians 3:26).
Pope John Paul II has also made universalistic noises: 'Man—every man without exception whatever—has been redeemed by Christ and...with man, with each man without any exception whatever, Christ is in a way united, even when man is unaware of it.' It is curious to find the pope appearing to endorse universalism, which stands on its head other Roman Catholic teaching about the fate of unrepentant sinners.
As these notes show, universalism has had a very bumpy history, and attracted a mixed bag of friends." 
Now go through this video wherein MSNBC host, Martin Bashir, interviews Rob Bell about the latter's new pro-universalism book (if it looks like a German Shepherd and barks, then it must be a dog). You will see that Bell echoes to a tee, in not so many words, the major universalist arguments presented above. It pays to know your history.
 John Blanchard, Whatever Happened to Hell [New York: Evangelical Press, 2003], 189).
 Ibid., 190-193.