12 Prologue Whoever teaches must become “all things to all men” ( 1 Cor 9:22), to win everyone to Christ. . . . Above all, teachers must not imagine that a single kind of soul has been entrusted to them, and that consequently it is lawful to teach and form equally all the faithful in true piety with one and the same method! Let them realize that some are in Christ as newborn babes, others as adolescents, and still others as adults in full command of their powers. . . . Those who are called to the ministry of preaching must suit their words to the maturity and understanding of their hearers, as they hand on the teaching of the mysteries of faith and the rules of moral conduct. 18 Above All—Charity 25 To conclude this Prologue, it is fitting to recall this pastoral principle stated by the Roman Catechism : The whole concern of doctrine and its teaching must be directed to the love that never ends. Whether something is proposed for belief, for hope or for action, the love of our Lord must always be made accessible, so that anyone can see that all the works of perfect Christian virtue spring from love and have no other objective than to arrive at love. 19 18 Roman Catechism, Preface, 11; cf. 1 Cor 9:22; 1 Pet 2:2. 19 Roman Catechism, Preface, 10; cf. 1 Cor 13:8.