1 Our first duty is to spread the name and reign of Christ more widely every day, and to call back the mutinous and the wandering to the bosom of the Church; this has occupied Our concern for a long time. For this reason We never cease to safeguard and multiply pious projects and to support them with the help gathered from the Catholic people. By this means the powerful light of Christian wisdom is spread among the erring. We did this especially in the third year of Our pontificate with the encyclical letter Sancta Dei Civitas in order to win for the illustrious Society for the Propagation of the Faith both greater support and generosity from the faithful. Then We were pleased to follow with exhortations showing how it had grown in a short time, from small beginnings to so large a stature; and with what testimonies of praise and grants of indulgences Our illustrious predecessors, Pius VII, Leo XII, Pius VIII, Gregory XVI, Pius IX had honored it. Finally, Our exhortations demonstrated how much aid had been given to the sacred missions throughout the world from this source, and how much more was to be expected. Nor by God's blessing was the fruit small in response to this exhortation. In the following years we saw the expansion of this most worthy work, since the generosity of the faithful responded to the zeal and the perseverance of the bishops. But now there is a new need and one more grave, which may demand that the spirit of Catholic love become more wide-spread. Venerable Brethren, may it stimulate your skill.
Source: Christi Nomen (Vatican.va)