40 Religious institutes of the contemplative and of the active life have so far played, and still do play, the main role in the evangelization of the world. This sacred synod gladly acknowledges their merits and thanks God for all that they have expended for the glory of God and the service of souls while exhorting them to go on untiringly in the work which they have begun, since they know that the virtue of charity, which by reason of their vocation they are bound to practice with greater perfection, obliges and impels them to a truly catholic spirit and work. Institutes of the contemplative life, by their prayers, sufferings, and works of penance have a very great importance in the conversion of souls, because it is God who sends workers into His harvest when He is asked to do so (cf. Matt. 9:38) God who opens the minds of non - Christians to hear the Gospel (cf. Acts 16:14), and God who fructifies the word of salvation in their hearts (cf. 1 C,or. 3:7). In fact, these institutes are asked to found houses in mission areas, as not a few of them have already done, so that there, living out their lives in a way accommodated to the truly religious traditions of the people, they can bear excellent witness among non - Christians to the majesty and love of God, as well as to our union in Christ. Institutes of the active life, whether they pursue a strictly mission ideal or not, should ask themselves sincerely in the presence of God, whether they would not be able to extend their activity for the expansion of the Kingdom of God among the nations; whether they could possibly leave certain ministries to others so that they themselves could expend their forces for the missions, whether they could possibly undertake activity in the missions, adapting their constitutions if necessary, but according to the spirit of their founder; whether their members are involved as totally as possible in the mission effort; and whether their type of life is a witness to the Gospel accommodated to the character and condition of the people. Now since, under the inspiration of the Holy Spirit, secular institutes are daily increasing in the Church, their activity, under the authority of the bishop, could be fruitful in the missions in many ways as a sign of complete dedication to the evangelization of the world.
Source: Ad Gentes (Vatican.va)