But someone might say, Are we to proclaim nothing but that Christ died for us? Isn’t it enough to preach about this one time only? I have heard it so often and know it so well. Answer: The Jews were required to hold the deliverance from Egypt in remembrance not only once, but always, year after year. But should we Christians trouble ourselves continually to repeat the remembrance of the deliverance Christ wrought for us from sin, death, devil, and hell? Are you among those who say, I have heard it all before; why must I hear it again? If so, your heart has become dull, satiated, and shameless, and this food does not taste good to you. This is the same thing that happened to the Jews in the wilderness when they grew tired of eating manna. But if you are a Christian, you will never grow weary, but will long to hear this message often and to speak about it forever.
Martin Luther, Sermon for Maundy Thursday, April 2, 1534. From Complete Sermons of Martin Luther, vol. 5, page 463.