20 First of all it is to be observed that the person who had been called by God to evangelize distant non-Christian lands, has received a very great and sublime vocation. He consecrates his life to God in order to spread His Kingdom to the farthest ends of the earth. He does not seek what is his, but what is Christ's. He can apply to himself in a special way those beautiful sayings of St. Paul: "For Christ . . . we are ambassadors." "Though we walk in the flesh, we do not war according to the flesh." "To the weak I became weak that I might gain the weak." He must, therefore, consider the country he is going to evangelize as a second fatherland and love it with due charity. Furthermore let him not seek any earthly advantage for his own country or religious Institute, but rather what may help towards the salvation of souls. Certainly he should dearly love his fatherland and his Order, but the Church should be loved with a still more ardent devotion. And let him remember that nothing will be to the advantage of his own Order that is detrimental to the good of the Church.
Source: Evangelii Praecones (Vatican.va)