From Archbishop John Carroll:
For when it pleased God to institute a religion here on earth he surely did not intend that it should remain hidden in darkness and sequestered from the eyes of mankind. As it is to serve to glorify him, it cannot be sufficient for it to remain shut up in the secret of men’s hearts: it must be visible and by its splendor contribute to raise in us ideas worthy of the greatness of the master to whom it subjects us, and proposes as the object of our worship. For this purpose were ordained the public ceremonies of religion; the solemn celebration of our august mysteries; and in a word all the outward duties which accompany the service of God. If then we purpose merely to confine ourselves to a pretended religion of the heart; without drawing any outward appearances of it, we betray a disposition so severely condemned by Jesus Christ in these remarkable words (Lk 9:26). He that is ashamed of me, and of my words, of him likewise will the son of God be ashamed, him will he disavow on the great day of judgment, in the presence of his Father, and the angels, in the face of heaven and earth.
But the evil proceeds farther by our withholding from God our public and apparent testimony to his holy religion; and we transgress another important obligation, namely that of the example which every believer owes to the society of which he is a member. For we are all but one body in Christ, and that which strengthens and gives vigor to this mystical body is the common edification mutually given and received, and resulting from the outward functions of religion, which make the greater impression, as we are naturally more encouraged to imitate what we see. But if, on the other hand, this outward worship begins to be neglected, all languishes with it: the idea of religion itself begins to fade away in our minds; impiety avails itself of this neglect and introduces not only a disgust, but even a contempt of all public and every private worship. From hence may be concluded how important the duty is, to which I now exhort you, the duty of honoring your religion.