There are approximately 2 billion Christians in the world. One billion Roman Catholics, with the other billion divided up between Protestants, Eastern Orthodox, Anglicans, and non-denominational/independents.
Christians have been praying for the restoration of unity in the Christian Church ever since 1054 AD when the Pope in Rome and the Patriarch in Constantinople excommunicated each other. Five hundred years later, Luther and Calvin's Reformation further divided the Church.
Is it realistic to think that re-unification could ever happen?
I have my doubts, but here are my thoughts on the matter, for whatever they are worth:
The biggest gripes of the Orthodox with the "Latin" church seems to be the
filioque and the claim of supremacy by the Roman Pope.
The
filioque was added by the "Latins" to the Nicene Creed years after the entire Christian Church had voted and approved the wording of the creed in the fourth century. Instead of stating that the Holy Spirit proceeds from the Father, the "Latins" changed it to state that the Holy Spirit "proceeds from the Father
and the Son."
The Orthodox also don't like the Roman Pope's claim to supremacy. In the early centuries of the church, he was just one of the five patriarchs. The other four were in Constantinople, Antioch, Jerusalem and Alexandria.
On the first issue, the Nicene Creed is extremely important, but it is not inspired scripture. It's
not worth dividing the Church over. The Western Church should take out the
filioque and return the Nicene Creed to its original wording.
The second issue is more tricky. Would the popes of Rome ever relinquish their supremacy? Doubtful, but if Roman Catholics want re-unification they are going to have to give on this issue.
What about a compromise? The pope could be referred to as the "First among equals". He, along with the Ecumenical Patriarch and maybe four or five newly elected Patriarchs from other Christian areas of the world, would govern the church "by committee", as in the early Church.
As an example, elections by the new bishops of a unified Church could elect new Patriarchs of Northern Europe, North America, South America, Asia, and Africa, with a representative mixture of Protestants, Catholics, Anglicans and Orthodox. The pope would be the spokesman and figurehead of the Church but would not have authority over the other patriarchs but an equal voice.
The government structure of the new Church could be as follows: Protestants would accept apostolic succession by having their bishops/presidents receive a laying on of hands from Orthodox, Roman Catholic and Anglican bishops. Roman Catholics would have to accept a "committee" form of government with all the patriarchs making procedural decisions by majority vote, but major doctrinal issues could only be settled by a super majority (80% a good number?) of a world wide church council of bishops, just as was done in the early Church.
What about the doctrinal and social issues that divide Roman Catholics/Orthodox from Protestants?
First of all, in my opinion, the biggest problem would not be the social issues. Both liberals and conservatives could agree to hold their respective noses and accept and tolerate their differences as followers of Christ.
However, I don't think that there is any realistic hope of conservative (orthodox) Christians maintaining unity with liberal Christians for much more than just a few more years. Why?
I will bet that within another generation (20-25 years) liberal Christians will no longer label themselves as Christians. "Christian" is an exclusionary term. It excludes alot of people in the world. Liberals like to be inclusive.
I predict that in 20 to 25 years, liberals will consider it politically incorrect, obnoxious and ignorant to state that Jesus is the "only way". And if Jesus is not the only way, why not abandon the exclusionary label of "Christian" for something more inclusive such as "humanist"?
So, I do not believe there is hope for orthodox (conservative) Christians to hold on to our liberal Protestant brothers and sisters. In time they will pull too far away from us to have any common Christian bond.
So who does that leave? It leaves conservative Lutherans, conservative Reformed, Anglo-Catholics, and believe it or not, evangelicals, to attempt some form of orthodox Christian unity with Roman Catholics and Eastern Orthodox.
Thirty years ago the idea of evangelicals united with Protestants, Orthodox, and Roman Catholics would have seemed absolutely ridiculous. But have you noticed the dramatic thawing of relations between evangelicals and Roman Catholics over the last few decades?
When I was a teenager 30 or so years ago, there were gospel tracts in my Baptist church on why we as Baptists should not vote for a Catholic president. Now, evangelical groups are endorsing Roman Catholic presidential candidates! Evangelicals have found alot of common ground with the Catholic Church on social issues, private schools, solidarity against government interference in religious institutions, etc..
So what would a union between Protestants and Catholics/Orthodox look like?
First, Catholics would have to accept Luther's doctrine of Justification by Faith alone. Protestants would then agree to a doctrine that states that both faith and works are absolutely necessary for Sanctification, appeasing Catholics.
Both Catholics and Protestants would agree that salvation is an act of God, not an act of man. Therefore exactly when in human time salvation actually occurs for each individual Christian would be left as a mystery, getting around the issue of baptism or an adult "born again" experience as the "when" of salvation.
The more important point of knowing
IF you are saved would be based on the two requirements mentioned in Romans 10:9, with no additional stipulations or clarifications.
Membership in the church would include only those who have been baptized in the name of the Father, Son and Holy Ghost. Infant or adult baptism would be optional. Immersion (being placed three times under the water) in living water would be the preferred method as it was in the early centuries (see the Didache). But it would not be mandatory; each parish church could decide it's own practice among the options of immersion, pouring, or sprinkling.
Holy Communion would be observed in the following terms: the real presence of Christ is present in the Holy Supper. Do you believe that God is omni-present? If you do then you believe that He is really present in the bread and wine of Holy Communion. Leave it at that. Any definition beyond that is left as a mystery so as not to re-open battles over transubstantiation, spiritual presence only or a symbolic memorial only.
Praying to saints would be an individual choice; neither encouraged nor discouraged by church authorities.
If I can ask my Christian brother, Bob, to pray for me while he is alive, where in the Bible does it say that he can't pray for me when he is in heaven? It doesn't, so leave it as an individual choice. The line must be drawn here, though: The Roman Catholic Church must agree that Mary, the Mother of God, will never be elevated to co-redeemer, as that action would be completely unacceptable to Protestants.
The last subject to resolve is actually the first subject that provoked the Reformation: Purgatory.
Without purgatory there would not have been a need for indulgences. Without indulgences, many of the abuses that so outraged Luther would probably not have occurred in the sixteenth century, and without an outraged Luther, there probably would not have been a Reformation.
Protestants will never accept the concept of purgatory and Catholics will probably never give it up.
Purgatory may be the deal-breaker for any re-unification of the Christian Church.
In conclusion, during the first few centuries of the Christian Church there was unity (for the mosr part) as all Christians were fighting against the persecution of an intolerant, secular world. Beginning in the fourth century and continuing into the twentieth century the "Christian world" has held sway.
The "Christian world" where Christian values dominate politics, morals and everyday life is fading. Intolerance to our faith may re-emerge. Maybe a new "persecution" of our faith and values will be the impetus for Christians to re-unify their Church.