TL/DR: Lutheranism isn’t so bad, but Luther was the very spawn of Satan.
I have frequently been accused of the fallacy of ad hominem against Lutheranism because of criticisms I have made against Luther, but that has never been my intent. Rather, I have argued that Catholicism does not simply hold the opposite theological position that Lutherans hold. I have been trying to enunciate the true Catholic faith, in the context of Lutheran theology, by pointing out that the Catholic Church had objections to Luther that even modern Lutherans would find quite reasonable. I’ve not tried to argue that Luther was evil, and therefore Lutherans are evil, but rather that Lutherans and Catholics are not so apart as the fact that the Catholic Church condemned Luther would suggest.
Luther preached that war should be made against the Church, even at the cost of tens of millions of lives, because the common-folk were damned to Hell by God, who considered their lives as meaningless cannon fodder.
Until the Muslims threatened the Princes whom Luther had led astray, Luther even preached that it would be a wonderful and blessed thing if Islam were destroy every last vestige of the Catholic Church, save the remnant that at the time existed only in Northern Germany.
He believed that if a person were inclined to sin, he should indulge in that sin with whole-hearted and reckless abandon, in the belief that by discovering his lack of guilt, he would understand the power of forgiveness, whereas the truth is such wanton sinfulness destroys the conscience and creates concupiscence to make reform more difficult, and that all sin brings evil and scandal upon the victims of that sin, which is the very reason Christ took sin upon himself.
He denied the canonicity of Hebrews, of the Apocalypse and the letters of John, the letters of Peter, and the Letter of James, for the sole reason that the Catholic Church had used those books to prove that what he had declared unbiblical to be biblical.
He asserted that the graces and charisms given to the Church were ineffective, that the very Will of God could be thwarted not only by the sinfulness of the subject of those graces, but by the sinfulness of the ministers of the Church of God through whom those graces flowed.
Many Lutherans (and other Protestants) have debated how fair or representative of Luther these facts are, but these are the accusations made against him which inspired the condemnation of the Church, and which rather than denying, he defended.
[Not germaine to THIS conversation, but the only reason I typically bring these horrors of Luther up is to point out that the Catholic Church does not believe in salvation by works, but through the Grace of God; that what the Church denied when it denied Solas Fides was not that Faith was necessary and Works were insufficient, but that Faith and Works were both signs of the Grace that was itself the source of all salvation. When the Church denied Sola Scriptura, it was not admitting that its doctrines were alien to scripture, but that especially when excised of the apocalypse of John, the scriptures were not self-defining and by their own testimony required the intervention of ministers of the Church to be understood properly; that the Catholic Church opposed the Gnostic notion that one could mystically interpret the Scriptures without assistance, learning or confirmation of Spirit.]
Sure, we could put it under the title of his last book “Of the Jews and their lies”.