13 Fully convinced as they are that the "highest dignity of the priesthood consists in the imitation of Christ"(15), churchmen must pay special attention to this warning of their Divine Master: "If anyone wishes to come after me, let him deny himself, and take up his cross and follow me." (16) It is recorded that "the holy parish priest of Ars often thought these words of the Lord over carefully, and determined to apply them to his own actions." (17) He made the resolution readily, and with the help of God's grace and by constant effort, he kept it to a wonderful extent; his example in the various works of priestly asceticism still points out the safest path to follow, and in the midst of this example, his poverty, chastity and obedience stand forth in a brilliant light.
Source: Sacerdotii Nostri Primordia (Vatican.va)