The Week of Prayer for Christian Unity began as a small initiative that grew in popularity over the years.
In 1908, Protestant pastor Paul Wattson organized it for the first time, though there had already been similar projects in the past.
Over time, Christians of different denominations joined the initiative. The Catholic Church officially joined in 1968.
In the northern hemisphere, it's celebrated from Jan. 18 to 25, from the former feast of the Confession of St. Peter to the feast of the Conversion of St. Paul.
In Rome, the pope concludes the week in the Basilica of St. Paul Outside the Walls, alongside other Christian leaders.
In the southern hemisphere, since the
Conversion of St. Paul usually falls during a vacation period, it's celebrated on another occasion, for example around Pentecost.
The theme this year is “That all may be one,” from the Gospel of St. John.
POPE FRANCIS
In these days, let us pray together so that Jesus’s desire might be accomplished: “That all may be one.” Unity, which is always superior to conflict.
Every year, a different Christian group is in charge of preparing the texts for reflection.
This year the task fell to the monastic community of Grandchamp, in Switzerland, formed by religious sisters of different Christian Churches and of a strong ecumenical vocation.
There are some 2.4 billion Christians around the world. The majority belong to one of the three large branches: Catholics, Orthodox and Protestants.
Javier Romero