You have also said very well that a characteristic of the priests of the Apostolic Union and their particular uniform must be, and is, in fact, love for the Pope, and this too will contribute admirably to your sanctification. To love him, it is enough to reflect on who the Pope is:
The Pope is the guardian of dogma and morality; he is the depository of the principles that make the family honest, the nations great, the souls holy; he is the counsellor of princes and peoples; it is the head under which no one feels tyrannized, because it represents God himself; He is the Father par excellence who brings together in himself everything that can be loving, tender, divine.
It seems incredible, and it is painful to do, that there are priests to whom I have to make this recommendation, but unfortunately we are in our day in this hard, unhappy condition of having to say to priests: love the Pope!
And how should we love the Pope? Non verbo neque lingua, sed opere et veritate. When you love a person, you try to conform to his thoughts in everything, to carry out his wishes, to interpret his desires. And if our Lord Jesus Christ said of himself: si quis diligit me, sermonem meum servabit, so to show our love for the Pope it is necessary to obey him.
Therefore when one loves the Pope, there is no discussion about what He disposes or demands, or how far obedience should go, and in what things one should obey; when one loves the Pope, it is not said that he has not spoken clearly enough, as if he were obliged to repeat in the ear of each one that will clearly expressed so many times, not only orally, but in letters and other public docuмents; his orders are not questioned, adducing the easy pretext of those who do not want to obey, that it is not the Pope who commands, but those around him; the field in which he can and should exercise his authority is not limited; the authority of the Pope is not put before that of other persons, however learned they may disagree with the Pope, who if they are learned are not saints, because he who is holy cannot disagree with the Pope.
This is the outpouring of a sorrowful heart, which I make with deep bitterness not for you, beloved brethren, but with you to deplore the conduct of so many priests, who not only allow themselves to discuss and scrutinize the Pope's wishes, but are not ashamed to arrive at impudent and brazen disobedience with so much scandal of the good and with so much ruin of souls.
This lament is not provoked (I repeat) by you, beloved confreres, who, observing the rules of the Union, solemnly profess your respect, your affection, your piety towards the Pope. - May God keep you in these holy purposes and comfort you with his blessing; that blessing that I invoke upon you, upon your confreres, upon your families, upon the people all dear to you and whom you have in mind, so that it may be for everyone. bringing every consolation.
https://www.vatican.va/content/pius-x/it/speeches/docuмents/hf_p-x_spe_19121118_unione-apostolica.html