The Church Unity Octave, a forerunner of the Week of Prayer for Christian Unity. Initially, the octave was that Anglicans, Old Catholics, Protestants, and Orthodox would be reunited with the Roman Catholic Church. When Pope Pius X gave his blessing to this time of prayer, the Church Unity Octave gained support among Roman Catholics, who, at the time, generally saw reunion in the terms of the return of Anglicans, Old Catholics, Protestants, and Orthodox to the Roman Catholic church.
The perspective of church unity was altered when a French priest, Fr. Paul Irénée Couturier (1881–1953), who was heavily influenced by the ideas of Jesuit Priest Pierre Teilhard de Chardin, refashioned the octave of prayer and took the emphasis off of reunion. Fr. Paul realized that the common prayer for unity was essential to the restoration of the unity of the churches. The new basis for the universal week of prayer proved to increase participation, and created a better basis for participation.
Two Anglican priests of the Franciscan community, Rev. Spencer Jones and Fr. Paul Watson, helped to develop the Week of Prayer for Christian Unity. The week of prayer was first observed at Graymoor in Garrison, NY, from January 18-25, 1908.
In 1966, the Faith and Order Commission of the World Council of Churches, and the Vatican Secretariat (now Council) for Promoting Christian Unity, began collaborating to prepare a basic text on a biblical theme. The text is jointly published by the Pontifical Council for Promoting Christian Unity and WCC, through the WCC's Commission on Faith and Order, which also accompanies the entire production process of the text. Since 1968 these international texts, have been developed, adapted and published for use in the United States by the Graymoor Ecumenical and Interreligious Institute. 
Today, the Week of Prayer for Christian Unity invites the whole Christian community throughout the world to pray in communion with the prayer of Jesus “that they all may be one” (John 17:21). The theme - "One in the apostles’ teaching, fellowship, breaking of bread and prayer" (Acts 2:42) - was chosen by a group of Christian leaders in Jerusalem. The leaders intend the theme as a call for inspiration and renewal, a return to the essentials of the faith, and a call to remember the time when the church was still one.
Where Could This All Lead?
One of the future goals of the Vatican is to move from Rome to Jerusalem. On September 26, 1973, the Houston Chronicle reported that Henry Kissinger proposed “that Jerusalem become an international city with the control of holy places and the religious administration being given to the pope.”
I'm speculating that when the Christian faith reunites with the Roman Catholic Church, if it be by the help of extraterrestrials or UN legislation, this will be when the Vatican will move, and the Pope will have control of the Church once again. For hundreds of years, the Pope has claimed to be god, and most have discounted his claims. The process toward the acceptance of Roman Catholicism as a legitimate faith, has been aided by the works of the ecumenical movement.
This rush towards unity is coming from the spirit of antichrist, who will deceive even the elect. Believers need to pray for discernment and then practice it.