Now see how much a man has to do, if he would do good works,
which always are at hand in great number, and with which he is
surrounded on all sides; but, alas! because of his blindness, he
passes them by and seeks and runs after others of his own
devising and pleasure, against which no man can sufficiently
speak and no man can sufficiently guard. With this all the
prophets had to contend, and for this reason they were all slain,
only because they rejected such self-devised works and preached
only God's commandments, as one of them says, Jeremiah vii: "Thus
saith the God of Israel unto you: Take your burnt offerings unto
all your sacrifices and eat your burnt-offerings and your flesh
yourselves; for concerning these things I have commanded you
nothing, but this thing commanded I you: Obey My voice (that is,
not what seems right and good to you, but what I bid you), and
walk in the way that I have commanded you." And Deuteronomy xii:
"Thou shalt not do whatsoever is right in thine own eyes, but
what thy God has commanded thee."

These and numberless like passages of Scripture are spoken to
tear man not only from sins, but also from the works which seem
to men to be good and right, and to turn men, with a single mind,
to the simple meaning of God's commandment only, that they shall
diligently observe this only and always, as it is written, Exodus
xiii: "These commandments shall be for a sign unto thee upon
thine hand, and for a memorial between thine eyes." And Psalm i:
"A godly man meditates in God's Law day and night." For we have
more than enough and too much to do, if we are to satisfy only
God's commandments. He has given us such commandments that if we
understand them aright, we dare not for a moment be idle, and