St. Benedict of Nursia promulgated in his Rule that the monks should stay inside a monastery. The walls are his protection against the encroachment of the world. He must not leave the walls that protect him from the corrupting influence of the world that has turned pagan. He can only grow in maturity of faith inside the walls.
And it is their maturity of faith inside the monastery that will attract outsiders to follow and be one with them. They cannot, ordinarily, go out and recruit. The pagan world will swallow them up. So when St. Boniface and his small community went to Germany to evangelize them, he followed the same procedure. He brought the monks there to live a community and monastic life hoping that the German pagans would be attracted to the life and join them.
Today, both Benedictine monks and nuns had committed the fatal mistake of leaving the safety of the monastery to go out and “save” the world. Most of them, if not all had been swallowed by the paganism of our world.