24 Indeed, it was in this spirit that Our predecessor Benedict XV, in order to preserve the integrity of the concept of Catholic unity, which must inspire all missionary work, sternly warned of a danger which he did not hesitate to define in these words, and which must be avoided by missionaries in their thoughts, lest it jeopardize the effectiveness of their actions: "It would be a sad thing if any missionary should appear to be so oblivious of his dignity as to think of his country on earth rather than of his fatherland in heaven, and be excessively concerned with increasing the power and the glory of his own nation above all other nations. Such conduct would greatly impair the cause of the apostolate, and would cut the sinews of charity in his heart, while lowering his prestige in the eyes of the public." (46)
Source: Princeps Pastorum (Vatican.va)