The following comments from Luther were found on Dave Armstrong’s website:
From: Concerning Rebaptism: A Letter to Two Pastors (1528)
Found in Luther’s Works, Vol. 40, 225-262; translated by Conrad Bergendoff. Page numbers will precede the words, in brackets (a few comments of mine [Armstrong’s] will be bracketed in a smaller font):
In the first place I hear and see that such rebaptism is undertaken by some in order to spite the pope and to be free of any taint of the Antichrist. In the same way the foes of the sacrament want to believe only in bread and wine, in opposition to the pope, thinking thereby really to overthrow the papacy. It is indeed a shaky foundation on which they can build nothing good. On that basis we would have to disown the whole of Scripture and the office of the ministry, which of course we have received from the papacy. We would also have to make a new Bible.
. . . We on our part confess that there is much that is Christian and good under the papacy; indeed everything that is Christian and good is to be found there and has come to us from this source. For instance we confess that in the papal church there are the true holy Scriptures, true baptism, the true sacrament of the altar, the true keys to the forgiveness of sins, the true office of the ministry, the true catechism in the form of the Lord’s Prayer,  the Ten Commandments, and the articles of the creed . . . I speak of what the pope and we have in common . . . I contend that in the papacy there is true Christianity, even the right kind of Christianity and many great and devoted saints.
. . . The Christendom that now is under the papacy is truly the body of Christ and a member of it. If it is his body, then it has the true spirit, gospel, faith, baptism, sacrament, keys, the office of the ministry, prayer, holy Scripture, and everything that pertains to Christendom. So we are all still under the papacy and therefrom have received our Christian treasures.
. . . We do not rave as do the rebellious spirits, so as to reject everything that is found in the papal church. For then we would cast out even Christendom from the temple of God, and all that it contained of Christ. But when we oppose and reject the pope it is because he does not keep to these treasures of Christendom which he has inherited from the apostles. Instead he makes additions of the devil and does not use these treasures for the improvement of the temple. Rather he works  toward its destruction, in setting his commandments and ordinances above the ordinance of Christ. But Christ preserves his Christendom even in the midst of such destruction, just as he rescued Lot at Sodom . . . the Antichrist sits in the temple of God through the action of the devil, while the temple still is and remains the temple of God through the power of Christ.
. . . They [Anabaptists] ought to come to the aid of Christendom which Antichrist has in his grip and tortures. They take a severe stand against the pope, but they miss their mark and murder the more terribly the Christendom under the pope. For if they would permit baptism and the sacrament of the altar to stand as they are, Christians under the pope might yet escape with their souls and be saved, as has been the case hitherto. But now when the sacraments are taken from them, they will most likely be lost, since even Christ himself is thereby taken away.
[note that Luther thus – remarkably, considering the overall state of today’s Protestantism – places the many evangelical Protestants who believe in a merely symbolic baptism and Lord’s Supper, in a far more perilous spiritual state than Catholics]