Why is it that Christian religions appear to be so opposed to the concept of reincarnation?

In 1992, Pope John Paul II finally admitted in public that the Catholic Church had acted unfairly toward Galileo. By then, of course, Galileo had been dead for 350 years (he died on 8 January, 1642) . Soon afterwards, Isaac Newton pursued the concept of orbital force, but he too was condemned and it was not until recently that the Church finally admitted that the Earth was in solar orbit. Indeed, it was not until the summer of 1996 that the notion of Hell was abolished by the General Synod of the Anglican Church, and it was this very notion which had caused such problems for Galileo, Newton and others. The Catholic Church, on the other hand, maintains the notion of Hell - and so, in the eyes of Rome, the Anglican Protestants have now become heretics in this regard.

What goes around, comes around -- but sometimes very slowly. Why such slow progress?
Well, if you see that people resist change around you, especially the older generation, why not in something as old as the church. Another 1000 years more before the Catholic church would accept any new advances. Its a positive start.

As it turns out, this attitude is a departure from the origins of Christianity. Nowhere in the Bible is reincarnation repudiated, in fact it appears to be a concept that Jesus and his followers took pretty much for granted. Jesus himself speaks of John the Baptist as the return of Elias (Matthew 11:14 and 17:11, Mark 9:11-13). We must look to the development of the Roman Catholic Church and its doctrines to understand how the concept of reincarnation lost favor in Christian tradition.

The first 300 years after Jesus’ death, there were many variations of Christian doctrine as the new religion spread throughout the Roman Empire. A number of factions developed, some believing in reincarnation, some not, and the factions were frequently in conflict. In an attempt to consolidate his crumbling Roman Empire, the Emperor Constantine in 325 A.D. offered his official support to Christians if they would settle their differences and establish a unified set of beliefs. The resulting Council of Nicaea put together the foundation of the Roman Catholic Church and established a new doctrine, from which reincarnation was omitted. Christians were instructed to drop any belief that was not covered in the doctrine.

However, the belief in reincarnation did not disappear easily, and in fact persisted for centuries afterwards. It the early 13th century, the Pope launched a crusade against the Cathars, a reincarnationist Christian sect in Italy and Southern France, and wiped them out completely. This, and the ensuing Spanish Inquisition with its fatal intolerance for any deviance from strict church doctrine, was finally effective in forcing Christians to give up their belief in reincarnation – at least publicly!

Why should the early church care so much about this belief, which so many early Christians accepted? The truth was, reincarnation undermined the authority and power of the developing church. A believer in reincarnation assumes greater personal responsibility for his own spiritual evolution, relying less on the influence and control of priests, confessionals, and rituals to ward off eternal damnation. None of these trappings of the church were part of Jesus’ original teachings, they were added by the men who shepherded the developing religion. Early Christianity was subject to the same pitfalls many grass-roots movements face when their original leaders are gone. Of necessity, the followers begin to establish a structure and organization to carry on what was given to them. In the process, some valuable elements can be lost and even replaced by dogma that has more to do with practical concerns (like church finances) than spiritual ideals. Reincarnation has never been in conflict with the tenets of Christ’s teachings, merely in conflict with the control wielded by the church.

by Ann C Barham.
sources:
wikipedia.com
pastlives.org
catholic.com
karenlyster.com/body_bookish1.html

Pope has been piped down in home country.
http://www.cnn.com/2008/WORLD/europe/01/15/pope.protest/