In the morning, when you rise, you shall make the sign of the holy cross, and you shall say: In the name of the Father, and of the Son, and of the Holy Spirit. Amen. Then, kneeling or standing, you shall say the Apostles’ Creed and the Lord’s Prayer. (“Prayers for Daily Use,” The Small Catechism, An Explanation of Dr. Martin Luther’s Small Catechism [Mankato, Minnesota: Evangelical Lutheran Synod, 2001], p. 26)
In the evening, when you go to bed, you shall make the sign of the holy cross, and you shall say: In the name of the Father, and of the Son, and of the Holy Spirit. Amen. Then, kneeling or standing, you shall say the Apostles’ Creed and the Lord’s Prayer. (“Prayers for Daily Use,” The Small Catechism, An Explanation of Dr. Martin Luther’s Small Catechism [Mankato, Minnesota: Evangelical Lutheran Synod, 2001], p. 26)
To defy the devil, I say, we should always keep the
holy name upon our lips so that he may not be able to harm us as he
would like to do. For this purpose it also helps to form the habit of
commending ourselves each day to God – our soul and body, spouse,
children, servants, and all that we have – for his protection against
every conceivable need. This is why the Benedicite, the Gratias, and
other evening and morning blessings were also introduced and have
continued among us. From the same source comes the custom learned in
childhood of making the sign of the cross when something dreadful or
frightening is seen or heard, and saying, “Lord God, save me!” or,
“Help, dear Lord Christ!” and the like. (Large Catechism I:72-74, The Book of Concord, edited by Robert Kolb and Timothy J. Wengert [Minneapolis: Fortress Press, 2000], pp. 395-96)
[Psalm 118:]5. Out of my distress I called on the Lord; the Lord answered me and set me free.
... You must never doubt that God is aware of your distress and hears
your prayer. You must not pray haphazardly or simply shout into the
wind. Then you would mock and tempt God. It would be better not to pray
at all, than to pray like the priests and monks. It is important that
you learn to praise also this point in this verse: “The Lord answered me
and set me free.” The psalmist declares that he prayed and cried out,
and that he was certainly heard. If the devil puts it into your head
that you lack the holiness, piety, and worthiness of David and for this
reason cannot be sure that God will hear you, make the sign of the
cross, and say to yourself: “Let those be pious and worthy who will! I
know for a certainty that I am a creature of the same God who made
David. And David, regardless of his holiness, has no better or greater
God than I have.” There is only one God, of saint and sinner, worthy and
unworthy, great and small. Regardless of the inequalities among us, He
is the one and equal God of us all, who wants to be honored, called on,
and prayed to by all. (“Psalm 118,” Luther’s Works, Vol. 14 [Saint Louis: Concordia Publishing House, 1958], pp. 58,61)
This is how it works. You denounce a man for his
unbelief and greed, and you hold the First Commandment up to him (Ex.
20:3): “You shall have no other gods before Me.” That is, “You shall not
attach your heart, your desire, and your love to anyone else but Me.”
And he refuses to hear that denunciation or to stand for it. He starts
ranting and raving against it, until in his heart there is bitterness
and venomous hatred against the Word and its preachers. That is why the
text of the Ten Commandments contains the threat (Ex. 20:5): “I am a
jealous God, visiting the sins of the fathers upon the children of those
who hate Me.” He is talking about these very same greedy bellies and
Mammon-servers, for Scripture calls greed “idolatry,” or the worship of
idols (Eph. 5:5; Col. 3:5). And yet, as we have said, they lay claim to
titles like “the greatest of saints” and “enemies of idolatry and
heresy”; and they absolutely disclaim the title “haters of God.” But
they are convicted by their inability to hear or see the Word of God
when it attacks their greed, and by their insistence that they get off
without any denunciation. The more they are denounced and threatened,
the more they deride and mock, doing whatever they please to spite God
and everyone else. Now, is that not a horrible disease and an abominable
sin, one that should terrify us so that we hate Mammon from the heart,
make the sign of the cross against him and run away as from the devil?
Who would not be terrified to fall into this and to hear this judgment
spoken over him? (“The Sermon on the Mount,” Luther’s Works, Vol. 21 [Saint Louis: Concordia Publishing House, 1956], pp. 190-91)
...God does not desire that you should learn from the
dead and seek the truth from them. He wants to be your living,
abundant, and satisfying teacher himself. You must cling to his word. He
knows well what he ought to tell you about the living and the dead, for
he knows all things. What he does not tell you or refuses to say, you
should not seek to know, but do him so much honor as to believe that he
realizes it is neither necessary nor useful nor good for you to know. So
you should happily and gladly cast to the winds all this swindle of the
spirits and not be afraid of them; doubtless they will then also depart
from you in peace. If you should have a poltergeist and tapping spirit
in your house, do not go and discuss it here and there, but know that it
is not a good spirit which has not come from God. Cross yourself
quietly and trust in your faith. (“Sermon for the Festival of the
Epiphany,” Luther’s Works, Vol. 52 [Philadelphia: Fortress Press, 1974], pp. 178-79)
...how do I approach this Savior and Redeemer? By
means of cowls or monastic orders and rules? No! Just cling to the Son
in faith. He conquered death and the devil, and He slit the devil’s
belly open. He will reign and rule again, even though He was crucified
under Annas and Caiaphas. Therefore attach yourself to Him, and you will
tear through death and devil; for this text [John 3:15] assures us:
“Whoever believes in Him shall have eternal life.” Accept the truth of
this miracle of God’s love for the world, and say: “I believe in the Son
of God and of Mary, who was lifted up and nailed to the cross.” Then
you will experience the new birth; for death and sin will no longer
accuse, harm, and injure you. Whoever believes in the Son will have
eternal life. Cling to His neck or to His garment; that is, believe that
He became man and suffered for you. Cross yourself and say: “I am a
Christian and will conquer.” And you will find that death is vanquished.
In Acts 2:24 St. Peter says that death was not able to hold Christ,
since deity and humanity were united in one Person. In the same way we,
too, shall not remain in death; we shall destroy death, but only if we
remain steadfast in faith and cling to death’s Destroyer. (“Sermons on
the Gospel of St. John,” Luther’s Works, Vol. 22 [Saint Louis: Concordia Publishing House, 1957], p. 356)
I have also read of a number of people who, when
persistently assailed by the devil, crossed themselves and spoke these
words: “The Word became flesh” [John 1:14], or the equivalent: “I am a
Christian!” with the result that the devil was beaten and put to flight
and their peace of mind was restored. And I believe this to be true, so
long as the words are spoken from a believing heart. Little is gained
against the devil with a lengthy disputation; but a brief word and reply
such as this is effective: “I am a Christian, of the same flesh and
blood as my Lord Christ, the Son of God. You settle with Him, devil!”
Such a retort would soon make him depart. It is certain that if anyone
could speak these words “And the Word became flesh” in true faith and
with strong confidence in hours of the greatest temptation, he would be
delivered from his trouble and distress; for the devil fears these words
when they are uttered by a believer. I have often read and also
witnessed it myself that many, when alarmed and distraught, spoke these
words “And the Word became flesh” and at the same time made the sign of
the cross, and thereby routed the devil. Belief in these words was so
powerful that it overcame the world and the devil. (“Sermons on the
Gospel of St. John,” Luther’s Works, Vol. 22 [Saint Louis: Concordia Publishing House, 1957], p. 106)
...we dare not trifle with the sacraments. Faith must
be present for a firm reliance and cheerful venturing on such signs and
promises of God. What sort of a God or Savior would he be who could not
or would not save us from sin, death, and hell? Whatever the true God
promises and effects must be something big. But then the devil comes
along and whispers into your ear, “But suppose you received the
sacraments unworthily and through your unworthiness robbed yourself of
such grace?” In that event cross yourself and do not let the question of
your worthiness or unworthiness assail you. Just see to it that you
believe that these are sure signs, true words of God, and then you will
indeed be and remain worthy. Belief makes you worthy; unbelief makes you
unworthy. (“A Sermon on Preparing to Die,” Luther’s Works, Vol. 42 [Philadelphia: Fortress Press, 1969], pp. 109-10)
...we know and have no other sacrifice than that
which he [Christ] made on the cross, on which he died once for all as
the Epistle to the Hebrews [9:12,26] says, and thereby put away the sins
of all men and also made us holy for eternity. That, I say, is our
gospel, that Christ has made us righteous and holy through that
sacrifice and has redeemed us from sin, death, and the devil and has
brought us into his heavenly kingdom. We have to grasp this and hold it
fast through faith alone. ... Now if this gospel is true, then
everything that offers another way or another sacrifice must be false.
But in the mass the papists do nothing but continually ride the words
“we offer up, we offer up” and “these sacrifices, these gifts.” They
keep completely quiet about the sacrifice that Christ has made. They do
not thank him. Indeed, they despise and deny his sacrifice and try to
come before God with their own sacrifice. ... The good Christ is not
pleasing to the Father unless the holy canon comes and makes him
pleasing, in that the offering reconciles him with God. And so again
Christ is dead and of no avail, since only the work is supposed to
forgive sins and obtain favor with God so that he is gracious to Christ
and to us. You see, there you have heard the holy secret mass, so that
you may know what it is and may be shocked by it and may cross yourself
as you would before the devil himself. ... Therefore, dear Christians,
let us flee from such an abomination... (“The Abomination of the Secret
Mass,” Luther’s Works, Vol. 36 [Philadelphia: Fortress Press, 1959], pp. 313,327-28)
... I am not contending against the sacrament but
against the mass, and would like to separate the sacrament from the mass
so that the mass might perish and the sacrament alone, without the
mass, might be preserved in its honor and according to the ordinance of
our dear Lord Jesus Christ. May God grant to all devout Christians such
hearts that when they hear the word “mass,” they might be frightened and
make the sign of the cross as though it were the devil’s abomination;
on the other hand, when they hear the word “sacrament” or “Lord’s
Supper,” they might dance for pure joy, indeed, in accordance with
genuine spiritual joy, cry sweetly. For I am very fond of the precious,
blessed Supper of my Lord Jesus Christ in which he gives me his body and
blood to eat and to drink even bodily with my own mouth along with
these exceedingly sweet and kind words: “Given for you, shed for you,”
etc. I am the more hostile and angry about the mass, because the papists
have thereby arrogated the holy sacrament to themselves alone, have
taken it from [Christians] and robbed Christians of it, and have made a
business of it and yet have woven both into one another so inseparably
when they provide it for Christians at Easter time, that the common man
is unable to distinguish between the mass and the sacrament. ... Yet
they are not one and the same thing. It is the mass when I sacrifice the
sacrament to God for my sins and the sins of others as a work performed
by human beings (whether they be evil or godly). This they have to
acknowledge. It is the sacrament when I receive from the priest the body
and blood of our Lord Jesus Christ under the bread and wine. (“A Letter
of Dr. Martin Luther Concerning his Book on the Private Mass,” Luther’s Works, Vol. 38 [Philadelphia: Fortress Press, 1971], pp. 226-27)
I only desire to have the conscience free and to
have all Christians make the sign of the cross against a faith which
believes that the pope is right in his rule. For such a faith destroys
faith in Christ and drowns the whole world in nothing but sin and
destruction. The pope and you papists are the pious heirs of this sort
of thing. You, who do no more than propagate such superstition, seduce
the world, destroy Christian faith, and lead all souls to the devil when
you should believe only in Christ and preach freedom from human laws so
as to remain “ministers of the Spirit” and not “of the letter” [cf. II
Cor. 3:6]. (“Answer to the Hyperchristian, Hyperspiritual, and
Hyperlearned Book by Goat Emser in Leipzig,” Luther’s Works, Vol. 39 [Philadelphia: Fortress Press, 1970], p. 202)
...Peter says, “You are Christ, the Son of the living
God” [Matt. 16:16]. Now blessed is he who has this confession of
Christ. Reason cannot come this far. This is made known by Christ
Himself when He answers Peter and says, “Blessed are you, Simon, son of
John. Flesh and blood has not revealed this to you, but my Father in
Heaven.” And He says further, “You are Peter (that is, a rock) and upon
this rock I will build My church and the gates of hell shall not prevail
against it” [Matt. 16:17-18]. ...that rock is Christ and his Word. For
Christ is known only through His Word. ... Upon that Word I then build.
... Therefore “rock” here means nothing else but the Christian
evangelical truth, which Christ makes known to me here. By this I ground
my conscience upon Christ and against this all other might is
ineffectual, even the gates of hell. Without this rock and foundation no
other can be laid. As Saint Paul says to the Corinthians, “No one can
lay any other foundation apart from that which is laid, which is Christ
Jesus” [1 Cor. 3:11]. ... Therefore Christ alone is the rock. Where any
other foundation is laid, then make the sign of the cross over yourself,
for surely the devil is there to lay it. For this passage cannot be
interpreted in any way but only that it speaks of Christ. (Sermon for
“The Feast of Saints Peter and Paul, the Holy Apostles,” Luther’s Festival Sermons [Dearborn, Michigan: Mark V Publications, 2005], Church Postils, Summer Section, pp. 89-91)
...clandestine betrothals...deprive God and parents
of the obedience due them... Therefore, I am determined that no
clandestine betrothal shall be approved, even if the father gives his
consent, because that only confirms the work of the devil. From the
beginning of the world, the only true way of doing this – among the
Gentiles, the papacy, and among us – has been for the parents on both
sides to come together and give their children in marriage... Whatever
is contrary to this is against God, who has forbidden it, and this
method prevailed until the present day among both the Gentiles and the
Jews. Afterward came the devil’s head at Rome with his other way of
doing it, the devil’s way, which is this: because the son intends to do
something honorable, namely, get married, he can do this without the
knowledge and consent of his parents, whether father or mother. That is
such an evil thing that one can scarcely say it aloud. God says, “Honor
your father.” The pope says, “That is not necessary if your intention is
to do something honorable.” Consider whether it is God or the pope who
speaks properly. God says, “Honor.” The pope says, “No, but I say that
you may well [do otherwise],” etc. There make the sign of the cross.
(“Sermon for the Second Sunday after Epiphany” [1544], Luther’s Works, Vol. 58 [Saint Louis: Concordia Publishing House, 2010], pp. 83-84)
In Haggai 2[:6-9] we read: “For thus says the Lord of
hosts: once again, in a little while, I will shake the heavens and the
earth and the sea and the dry land; and I will shake all nations, so
that the consolation of the Gentiles (chemdath) shall come, and I
will fill this house with splendor, says the Lord of hosts. The silver
is mine, and the gold is mine, says the Lord of hosts. The splendor of
this latter house shall be greater than the former, says the Lord of
hosts; and in this place I will give prosperity, says the Lord of
hosts.” This is another of those passages which pains the Jews
intensely. They...take up and crucify the expression “consolation of the
Gentiles,” in Hebrew chemdath... They insist that this term does
not refer to the Messiah, but that it designates the gold and silver of
all the Gentiles. Grammatically, the word chemdath really means
desire or pleasure; thus it would mean that the Gentiles have a desire
for or take pleasure and delight in something. ... What do the Gentiles
desire? Gold, silver, gems! ... Further, how does it happen that such
very intelligent teachers and wise, holy prophets do not also apply the
word “desire” (chemdath) to all the other desires of the
Gentiles? For the Gentiles desire not only gold and silver but also
pretty girls, and the women desire handsome young men. ... Why, then, do
the Jews not interpret this verse of the prophet to mean that such
desires of all the Gentiles also will shortly come to Jerusalem, so that
the Jews alone might fill their bellies and feast on the world’s joys?
For such a mode of life Muhammad promises his Saracens. In that respect
he is a genuine Jew, and the Jews are genuine Saracens according to this
interpretation. ... Therefore, dear Christian, be on your guard against
the Jews, who...are consigned by the wrath of God to the devil, who has
not only robbed them of a proper understanding of Scripture, but also
of ordinary human reason, shame, and sense, and only works mischief with
Holy Scripture through them. ... For anyone who dares to juggle the
awesome word of God so frivolously and shamefully as you see it done
here...cannot have a good spirit dwelling in him. Therefore, wherever
you see a genuine Jew, you may with a good conscience cross yourself and
bluntly say: “There goes a devil incarnate.” (“On the Jews and Their
Lies,” Luther’s Works, Vol. 47 [Philadelphia, Fortress Press, 1971], pp. 209-14) 
Note:
When Luther speaks of “a genuine Jew” and “a devil incarnate,” he is
not saying that Jewish people as a racial group are devils, but he is
referring to the demonic “spirit” that he perceives to be dwelling
within false teachers and false prophets (whether Jews or Gentiles) who
“juggle the awesome word of God so frivolously and shamefully.” The fact
that Luther also calls Muhammad “a genuine Jew” demonstrates that he is
using this phrase as a description of someone who adheres to a certain
kind of belief system, and not as a description of someone who belongs
to a particular ethnic group. At the conclusion of the treatise from
which this quotation is taken, Luther says (in regard to the Jews) that
he wants his readers “to understand not only that their belief is false
but that they are surely possessed by all devils.” He then immediately
goes on to express this prayerful wish: “May Christ, our dear Lord,
convert them mercifully...” (p. 306).
ADDENDA:
Among all the ancient writers there is indeed
frequent mention of the sign of the cross. ...at the time of Tertullian
and afterward the Christians with their fingers formed a transverse
figure like a cross in the air, and in this way identified themselves.
It was...a profession and reminder that they believed in Christ
crucified, and that they were placing all their hope and confidence in
Him. (Martin Chemnitz, Examination of the Council of Trent, Part IV [Saint Louis: Concordia Publishing House, 1986], p. 94)
If you are tempted, hasten to sign yourself on the
forehead against the devil, provided you make it with faith, not for men
to see but knowing how to use it like a breastplate. Then the
adversary, seeing the power that comes from the heart, will flee. This
is what Moses imaged forth through the passover lamb that was
sacrificed, when he sprinkled the thresholds and smeared the doorposts
with its blood. He was pointing to the faith that we now have in the
perfect Lamb. By signing our forehead and eyes with our hand, we repulse
him who seeks to destroy us. (Hippolytus of Rome, “The Apostolic
Tradition” [ca. 215 A.D.], in Lucien Deiss, Springtime of the Liturgy [Collegeville, Minnesota: The Liturgical Press, 1979], p. 153)
