This quote is grossly out of context. Since seeing it posted here on Catholic Answers, I went and looked it up:
Luther: My word is the word of Christ; my mouth is the mouth of Christ
Regards,
James
Luther wrote:
Now every man—whether it be I or another—who speaks the word of Christ may boldly assert that his mouth is the mouth of Christ. I for my part am certain that my word is not mine, but the word of Christ; my mouth therefore must also be the mouth of him whose word it speaks
It sounds to me as if Luther was certain that God was speaking through him. If you read this quote in context, Luther goes on to think of himself as a prophet from God, that his task was to do away with the papacy, the priesthood, monasteries and religious vocations. In my opinion, what makes Luther an effective deceiver is that he speaks with half-truths. A half-truth is a deceptive statement that includes some element of truth, allowing for a rationalized acceptance of false statements. In Mark 13:6 Jesus Himself warns
“many shall come in my name, saying, I am he; and they shall deceive many.”
***When he is gone from men’s hearts and so has lost their confidence, he [the pope] is already destroyed. ***But the light of truth hurts him; when we contrast him [the pope] with Christ, and his teaching [the pope’s] with the gospel, that brings him down and utterly destroys him without any effort and exertion on our part. **See what I have done. Have I not, with the mouth alone, without a single stroke of the sword, done more harm to the pope, bishops, priests, and monks **than all the emperors, kings, and princes with all their power ever did before? And why? Because Daniel 8:25] says, “By no human hand shall this king be broken”; and St. Paul says, “He will be destroyed by the mouth of Christ”
I would surmise that it is not the mouth of Christ speaking through Luther but the spirit of the one who seeks to destroy the Church. Luther goes on to say:
Now every man—whether it be I or another—who speaks the word of Christ may boldly assert that his mouth is the mouth of Christ. I for my part am certain that my word is not mine, but the word of Christ; my mouth therefore must also be the mouth of him whose word it speaks . . . Christ himself has already begun an insurrection with his mouth. . .
So Luther was claiming that Christ, through the mouth of Luther, was causing an insurrection in the Church to do away with the false doctrines that the Church was teaching for 1,500 years? Then Luther claims the devil himself feared his coming:
*The devil has for a long time feared the coming of these years; he smelled the pot boiling a long way off. He even issued many prophecies against it, **some of which point to me, *** so I often stand amazed at his great cunning. Often he [the devil] would have liked to kill me. . .
The devil himself issued prophecies about Martin Luther? Where did the devil do this?
Get busy now; spread the holy gospel, and help others spread it; teach, speak, write, and preach that man-made laws are nothing;
Translate: Luther is teaching that the ancient doctrines of the Catholic Church are false, and that people should not believe them. But we know that the devil often masquerades himself as a follower of Christ. Paul clearly warned:
"just as Eve was deceived by the serpent’s cunning, your minds may somehow be led astray . . .For if someone comes to you and preaches a Jesus other than the Jesus we preached, or if you receive a different spirit from the Spirit you received,** or a different gospel from the one you accepted,** you put up with it easily enough. . . such people are false apostles, deceitful workers,
masquerading as apostles of Christ. And no wonder, for Satan himself masquerades as an angel of light.
It is not surprising, then, if his servants also masquerade as servants of righteousness." 1 Cor. 11:3-15
Here’s the kicker:
urge people not to enter the priesthood, the monastery, or the convent, and hinder them from so doing; encourage those who have already entered to leave; give no more money for bulls, candles, bells, tablets, and churches; rather tell them that a Christian life consists of faith and love.* Let us do this for two years, and you shall see what will become of pope, bishops, cardinals, priests, monks, nuns, bells, towers, masses, vigils, cowls, hoods, tonsures, monastic rules, statutes, and all the swarming vermin of the papal regime; they will all vanish like smoke.***
Yes indeed, a Christian life consist of faith and love, but without the priesthood we have no valid sacraments; without the sacraments we lose the primary means of sanctifying grace established by Christ through His Church. Without the Sacrifice of the Mass we have no Holy Eucharist. This is how the devil works. He goes after priests so that there is no Holy Sacrifice of the Mass. I can only surmise that Luther’s words are from the spirit of darkness, not the Holy Spirit.
Luther continues:
But if we fail to teach and spread this truth among the people so their hearts will no longer cling to these things, we will still have the pope with us, though we were to start a thousand insurrections against him. Just see what has been accomplished in this one single year, during which we have been preaching and writing this truth!
Again we echo the words of Paul:
For such people are . . .masquerading as apostles of Christ. I believe Luther was naive and blinded by his pride, unwittingly becoming an instrument of the devil, accomplishing the task of spreading the “truth” so that the hearts of people would no longer believe the same teachings of the Church which the Early Church Fathers defended against the heretics of their day. But the good news is that Jesus said:
And I tell you that you are Peter, and on this rock I will build my church, and the gates of Hades will not overcome it. I will give you the keys of the kingdom of heaven;* whatever you bind on earth will be bound in heaven**, and whatever you loose on earth will be loosed in heaven.”*
Luther was ex-communicated from the Church and his legacy is confusion, division and false doctrines. One need not read all of Luther’s references to excrement and farts he hurled in his writings against the pope, the teaching of the Church, and the authority of the Church, to realize that this man was not sent from God. The devil is an expert at deceiving people, thus I hope that poor Martin Luther, whom I believe unwittingly thought he was doing good, somehow by the grace of God made it to Purgatory and is making amends for all the all the false teachings his tongue and pen introduced into the minds of men. Thus we must watch and pray, for we are at war against the forces of deception. The key is to remember that false teachers* masquerade as apostles of Christ.*
"For our wrestling is not against flesh and blood; but against principalities and power, against the rulers of the world of this darkness, against the spirits of wickedness in the high places."Ephesians 6:12 found 2
Luther did not ‘throw out’ the DC as you say … but, unfortunately, just leaving it right there as though Luther did nothing in this regard is misleading! 
