27 Since it is necessary in order to organize the Church in these regions, as We have already remarked, that you make use of the very elements out of which under Divine Providence they have been composed, you ought as a consequence to consider the founding of religious Congregations of men and women made up of natives to be one of the principal duties of your holy office. Is it not meant that these newly born followers of Christ be able to follow a life of evangelical perfection if they feel themselves called to take the vows of religion? With reference to this point, the missionaries and nuns who labor in your dioceses should not permit themselves to become prejudiced out of sheer love each for his own religious Congregation, a love which in itself is undoubtedly sound and legitimate. They should learn to view this matter broadly and to act accordingly. Therefore, if there are natives who desire to join one or other of the older Congregations, it assuredly would not be right to dissuade them or to prevent their joining, provided, of course, they give signs of being able to acquire the spirit of these Congregations and of establishing in their own countries houses of the Order which shall not be unworthy of the Congregation of which they are members. Perhaps it would be well if you would consider seriously and without admixture of selfinterest, if it would not be more advantageous all around to establish entirely new Congregations, which would correspond better with the genius and character of the natives and which would be more in keeping with the needs and the spirit of the different countries. We cannot pass over in silence another point most important for the spread of the gospel, namely, the necessity of increasing the number of catechists. Catechists may be Europeans, or preferably natives, who help the missionaries in their work especially by instructing and preparing catechumens for baptism. It is quite unnecessary to write of the qualities which these catechists should possess in order to be able to draw to Christ those who do not believe in Him; this they can do more by the example of their lives than by word of mouth. You, Venerable Brothers and Beloved Sons, make a firm resolution to train them with all possible care in order that they may acquire a profound knowledge of Christian doctrine, and that in teaching the Faith they may be able to adapt themselves both to the natural abilities and the level of intelligence of their catechism classes. In this catechetical work their success will be in exact proportion to the intimate knowledge which they possess of the mental ability and habits of the natives.
Source: Rerum Ecclesiae (Vatican.va)