7 Communities which are entirely dedicated to contemplation, so that their members in solitude and silence, with constant prayer and penance willingly undertaken, occupy themselves with God alone, retain at all times, no matter how pressing the needs of the active apostolate may be, an honorable place in the Mystical Body of Christ, whose "members do not all have the same function" (Rom. 12:4). For these offer to God a sacrifice of praise which is outstanding. Moreover the manifold results of their holiness lends luster to the people of God which is inspired by their example and which gains new members by their apostolate which is as effective as it is hidden. Thus they are revealed to be a glory of the Church and a well-spring of heavenly graces. Nevertheless their manner of living should be revised according to the principles and criteria of adaptation and renewal mentioned above. However their withdrawal from the world and the exercises proper to the contemplative life should be preserved with the utmost care.
Source: Perfectae Caritatis (Vatican.va)