Therefore it is beneficial and proper for each person, in accordance with the orientation that he has chosen and the grace that he has received, to strive most zealously and diligently to attain to perfection in the work that be has undertaken. He may praise and admire the virtues of others, but he should never depart from the profession that he has once chosen, knowing that, according to the Apostle, the body of the Church is indeed one, although its members are many, and that it has, gifts differing according to the grace which has been given to us; whether prophecy, in proportion to our faith; or service, in our serving; or he who teaches, in teaching; or he who exhorts, in his exhortation. Some members cannot claim for themselves the ministries of other members, for the eyes cannot perform the function of the hands nor the nose of the ears. Therefore not all are Apostles, not all are Prophets, not all are teachers.
John Cassian
Conferences, 14:5
