Staying, remaining faithful implies an outgoing. Precisely if one remains in the Lord one goes out of oneself. Paradoxically precisely because one remains, precisely if one is faithful one changes. One does not remain faithful, like the traditionalists or the fundamentalists, to the letter. Fidelity is always a change, a blossoming, a growth. The Lord brings about a change in those who are faithful to Him. That is Catholic doctrine. Saint Vincent of Lerins makes the comparison between the biologic development of the person, between the person who grows, and the Tradition which, in handing on the depositum fidei from one age to another, grows and consolidates with the passage of time: «Ut annis scilicet consolidetur, dilatetur tempore, sublimetur aetate».
H/T William Doino