To be effective evangelisers, the Catholic Church and other Christian churches must constantly undergo their own conversion to a stronger commitment to Christian unity, said Cardinal Kurt Koch, the Vatican's chief ecumenist. "So that the evangelising task can be carried out in a credible way, the Church itself continually needs a self-evangelisation that includes conversion to the ecumenical search for Christian unity," the Swiss cardinal wrote in the Vatican newspaper, L'Osservatore Romano. In preparation for the annual Week of Prayer for Christian Unity from January 18-25, Cardinal Koch's article focused on the connection between mission and Christian unity, a connection that gave birth to the ecumenical movement among Protestants more than 100 years ago and one that the Catholic Church has acknowledged since the Second Vatican Council.