Pope Benedict XVI has posted his first Twitter message in Latin with the words, "Orare semper, iustitiam factitare, amare probitatem, humiles Secum ambulare".
Although Latin is no longer a spoken language, the pope used Latin on his Twitter account @pontifex saying, "Always pray, act for justice, love, goodness, and walk humbly with Him."
In the Week of Prayers for Christian Unity, the pontiff prefaced those words with the question: "What does the Lord ask of us as we work for Christian unity?"
Latin was the liturgical language of the Church of Rome before the Second Vatican Council that started under Pope John XXIII on 11 Oct. 1962 and closed under Pope Paul VI on 8 Dec. 1965.
Decisions of the council were followed by an estrangement of the Vatican with Traditional Catholics, favoring the Latin liturgy.
Pope Benedict has sought to heal the rift with Traditional Catholics by a number of gestures, including encouraging more use of Latin by Catholics.
Meanwhile, Anglicans, Orthodox, Protestants and Roman Catholics in the northern hemisphere join Friday for one week to pray together for a week of Christian unity.
The Week of Prayer for Christian Unity is traditionally celebrated between January 18-25 (in the northern hemisphere) or at the feast of Pentecost (in the southern hemisphere).
On Monday, the Holy See will host an Interreligious Service at the chapel of the Ecumenical Center at which the Permanent Representative of the Holy See to the United Nations, Monsignor Sivlano Tomasi, will lead the prayers.
Also giving submissions during the service at the Ecumenical Centre, which is the headquarter of the World Council of Churches, will be WCC General Secretary, the Rev. Olav Fyske Tveit and leaders from the Buddhist, Jewish and Muslim communities in Geneva.
Along with many other churches and denominations the Vatican has long embraced the latest communications tools to spread the faith.
The Italian Nobel Physics Prize Laureate and inventor of long distance radio transmission, Guglielmo Marconi, set up Vatican Radio in 1931 as a tool of evangelization.
The Vatican now also uses YouTube.