To Be a Theologian of the Cross

Christ has sacrificed himself once [Heb. 7:27, 9:25-26]; henceforth he will not
be sacrified by anyone else. He wished us to remember his sacrifice. Why are you
then so bold as to make a sacrifice out of this remembrance? Is it possible that
you are so foolish as to act upon your own devices, without any scriptural
authority? If you make a sacrifice out of the remembrance of his sacrifice, and
sacrifice him once more, why do you not also make another birth out of the memory
of his birth, so that he may be born once more? (The Misuse of the Mass, LW 36:147)

When Christ commanded us to do this in remembrance of him he wanted nothing more
from us than that with the promise and pledge we should exercise ourselves daily
in faith. This is why he instituted this sacrament and gave it to us, for the
human soul will be nourished more and more if one frequently remembers this
gracious promise. (The Misuse of the Mass, LW 36:169)

...the duty, remebrance, or requiem, which we are to do for Christ; that is, that
we should preach his love and grace, hear and mediate upon it, and by it be
incited and preserved unto love and hope in him. (Treatise on New Testament,
LW 35: 87)