Rite & Reason: As the annual week of prayer for Christian unity begins on Thursday, Michael Kellyargues that a liberal approach makes unity more difficult.
By the time Pope John XXIII called the Second Vatican Council (1962-1965), ecumenism had been flourishing in other Christian denominations since the late 19th and early 20th centuries. The Catholic Church remained wary of the ecumenical movement, opposing any form of unity that would create a diluted, middle-of-the-road form of Christianity that adherents of the various denominations could subscribe to without much change in their differing beliefs.
For Rome, Christian unity would have to involve the Orthodox Churches of the East and the Protestant communities formed since the Reformation returning to their Apostolic roots in the One, Holy, Catholic and Apostolic Church, made manifest in the Roman Catholic Church.
It is in this context that Vatican II's decree on ecumenism, Unitatis Redintegratio(1964), created a new theological and pastoral openness within Catholicism to dialogue and worship with other Christian traditions. The document affirmed the fact that the Holy Spirit works in other Christian traditions to bring about the salvation of non-Catholics. Basically put: one didn't need to be a Roman Catholic in order to go to heaven.
Vatican II led to many powerful and symbolic gestures between Christian leaders, including the lifting of the mutual excommunications between the Catholic Church and the Orthodox Church that had followed the Great Schism of 1054.
Another historic moment on the road to better reciprocated understanding was the visit of the then Archbishop of Canterbury Dr Michael Ramsey to Pope Paul VI in 1966.
But even more important than the gestures are the theological developments that have taken place in recent decades. They have seen enormous growth in understanding between the churches in areas of theology as well as in pastoral ministry.
The historic dispute between Catholics and Lutherans over "Justification" - God's act of declaring or making a sinner righteous before God - was settled after years of painstaking dialogue by the signing of a joint declaration on the doctrine between the two churches in 1999. News that the World Methodist Council, representing some 75 million Methodists worldwide, is to sign on to the same declaration has given added weight to this process of dialogue.
There have also been fruitful discussions between Anglicans and Catholics since the foundation of the Anglican Roman Catholic International Commission (ARCIC). Discussions on authority within the church and more recently on the place of the Blessed Virgin Mary within Christianity have gone a long way in clarifying complex teachings that have caused centuries of division and misunderstanding. The most recent report of ARCIC even goes so far as to say that the Catholic doctrines of the Immaculate Conception and of the bodily Assumption of Mary into heaven, properly understood, are acceptable to Anglicanism.
Despite these and other significant developments, fresh challenges have arisen in recent years that make ecumenical progress more difficult and in some instances near impossible.
The decision by the Anglican Communion to ordain women a number of years ago opened up a new rift not only with the Catholic Church but also between Anglicans and the Orthodox world as well. Fresh tensions within Anglicanism over the consecration of active homosexuals as bishops have led to a state of virtual paralysis in meaningful dialogue between Anglicans and Christians of either the Catholic or Orthodox traditions.
Since his election almost two years ago, Pope Benedict has underlined the fact that he sees relations with the East as being of paramount importance. This is not to say that dialogue between Rome and the Protestant denominations will not continue, but it may be that the Catholic Church will pursue an ecumenism at two speeds, reflecting the new realities that have arisen in recent years.
Despite the optimism of the years immediately following Vatican II, it has become increasingly clear in recent years that Christian unity will be a long and arduous process. Theological liberalism resulting in women's ordination and the consecration of active homosexuals, as well as the apparent watering-down of once-cherished doctrines within some of the Protestant denominations, has led to a situation where Christian unity seems impossible in the short term.
It is ironic that the liberal elements that once led the way in forcing the more hard-line elements within the Christian churches to embrace ecumenism are, by their insistence that their denominations take on more liberal positions on matters of faith and morals, making the cause of unity more difficult.
• Michael Kelly worked at Vatican Radio in Rome for a number of years and now writes for theIrish Catholic newspaper.