IV. Premature promotions are to be avoided.
But when the Apostle warns and says: “and let these also first be proved, and so let them minister,” what else do we think must be understood but that in these promotions we should consider not only the chastity of their marriages, but also the deserts of their labours, lest the pastoral office be entrusted to men who are either fresh from baptism, or suddenly diverted from worldly pursuits? For through all the ranks of the Christian army in the matter of promotions it ought to be considered whether a man can manage a greater charge.
Rightly did the venerable opinions of the blessed Fathers in speaking of the election of priests reckon those men fit for the administration of sacred things who had been slowly advanced through the various grades of office, and had given such good proof of themselves therein that in each one of them the character of their practices bore witness to their lives. For if it is improper to attain to the world's dignities without the help of time and without the merit of having toiled, and if the seeking of office is branded unless it be supported by proofs of uprightness, how diligently and how carefully ought the dispensing of divine duties and heavenly dignities to be carried out, lest in anything the apostolic and canonical decrees be violated, and the ruling of the Lord's Church be committed to men who being ignorant of the lawful constitutions and devoid of all humility wish not to rise from the lowest grade, but to begin with the highest: for it is extremely unfair and preposterous that the inexpert should be preferred to the expert, the young to the old, the raw recruits to those who have seen much service. In a great house, indeed, as the Apostle explains, there must needs be various vessels, some of gold and of silver, and some of wood and of earth: but their purpose varies with the quality of their material, and the use of the precious and of the cheap kinds is not the same. For everything will be in disorder if the earthen ware be preferred to the golden, or the wooden to the silver. And as the wooden or earthen vessels are a figure of those men who are hitherto conspicuous for no virtues; so in the golden or silver vessels they no doubt are represented who, having passed through the fire of long experience, and through the furnace of protracted toil have deserved to be tried gold and pure silver. And if such men get no reward for their devotion, all the discipline of the Church is loosened, all order is disturbed, while men who have undergone no service obtain undeserved preferment by the wrongful choice of the electing body.
Source: Letters (New Advent)