Abba Hilarion [founder of Palestinian monasticism] was asked, “How can it be right for a diligent brother not to be offended when he sees other monks returning to the world?” The old man said, “Let me tell you a story. Consider the hunting dogs which chase after hares; imagine one of these dogs sees a hare in the distance and immediately gives chase, the other dogs that are with him see this dog taking off and take off after him, even though they have not seen the hare. They will continue running with him, but only for a time; when at length the effort and struggle exhaust them, they give up the chase and turn back. However the dog that saw the hare continues chasing it by himself. He does not allow the effort or the struggle to hinder him from completing his long course. He risks his life as he goes on, giving himself no rest. He does not allow the turning aside of the other dogs behind him to put him off. He goes on running until he has caught the hare he saw. He is careless both of the stumbling blocks in his path, whether stones or thrones, and of the wounds they have afflicted.
So also the brother who wishes to follow after the love of Christ must fix his gaze upon the cross until he catches up with him that was crucified upon it, even though he sees everyone else has begun to turn back.”
(Budge, The Paradise of the Holy Fathers, 2.211)