This is one of my favorite quotes from the early Church Fathers about how to care for and pass on the Faith. Vincent was a Monk in the 5th century, who was ordained a priest in a monastery on the island of Lerins, located off the southern coast of what is now France.
“[Your Catholic Faith] has been entrusted to you, not that which you have yourself devised: a matter not of wit, but of learning; not of private adoption, but of public tradition; a matter brought to you, not put forth by you, wherein you are bound to be not an author but a keeper, not a teacher but a disciple, not a leader but a follower. ‘Keep the deposit.’ Preserve the talent of Catholic Faith inviolate, unadulterate. That which has been entrusted to you, let it continue in your possession, let it be handed on by you. You have received gold; give gold in turn. Do not substitute one thing for another. Do not for gold impudently substitute lead or brass. Give real gold, not counterfeit.”
— St Vincent of Lerins, (d)445. Commonitory, Ch. 22, no. 53; CCC 166