Lastly, works of piety and charity are infinitely better than indulgences, and yet they do not preach these with such display or so much zeal; nay, they keep silence about them for the sake of preaching pardons. And yet it is the first and sole duty of all bishops, that the people should learn the Gospel and Christian charity: for Christ nowhere commands that indulgences should be preached. What a dreadful thing it is then, what peril to a bishop, if, while the Gospel is passed over in silence, he permits nothing but the noisy outcry of indulgences to be spread among his people, and bestows more care on these than on the Gospel!
— Introduction to the 95 Theses