35 But any habits whatever have so great power to hold possession of men's minds, that even what in them are evil, which usually takes place through excess of lusts, we can sooner disapprove of and hate, than desert or change. Do you think that little has been done for the benefit of man, that not some few very learned men maintain by argument, but also an unlearned crowd of males and females in so many and different nations both believe and set forth, that we are to worship as God nothing of earth, nothing of fire, nothing, lastly, which comes into contact with the senses of the body, but that we are to seek to approach Him by the understanding only?
That abstinence is extended even unto the slenderest food of bread and water, and fastings not only for the day, but also continued through several days together; that chastity is carried even unto the contempt of marriage and family; that patience even unto the setting light by crosses and flames; that liberality even unto the distribution of estates unto the poor; that, lastly, the contempt of this whole world even unto the desire of death? Few do these things, yet fewer do them well and wisely: but whole nations approve, nations hear, nations favor, nations, lastly, love.
Nations accuse their own weakness that they cannot do these things, and that not without the mind being carried forward unto God, nor without certain sparks of virtue. This has been brought to pass by the Divine Providence, through the prophecies of the Prophets, through the manhood and teaching of Christ, through the journeys of the Apostles, through the insults, crosses, blood, of the Martyrs, through the praiseworthy life of the Saints, and, in all these, according as times were seasonable, through miracles worthy of so great matters and virtues.
When therefore we see so great help of God, so great progress and fruit, shall we doubt to hide ourselves in the bosom of that Church, which even unto the confession of the human race from [the] apostolic chair through successions of Bishops, (heretics in vain lurking around her and being condemned, partly by the judgment of the very people, partly by the weight of councils, partly also by the majesty of miracles,) has held the summit of authority. To be unwilling to grant to her the first place, is either surely the height of impiety, or is headlong arrogance.
For, if there be no sure way unto wisdom and health of souls, unless where faith prepare them for reason, what else is it to be ungrateful for the Divine help and aid, than to wish to resist authority furnished with so great labor? And if every system of teaching, however mean and easy, requires, in order to its being received, a teacher or master, what more full of rash pride, than, in the case of books of divine mysteries, both to be unwilling to learn from such as interpret them, and to wish to condemn them unlearned?
Source: On the Profit of Believing (New Advent)