The study thoroughly investigates Martin Luther's comments in the Large Catechism II 66 that touch on the do Muslims, Christians, Jews, and pious philosophers all believe in and worship the same God? This study will walk you through the challenging history, interpretation, and translation of Luther's thoughts and will provide you with context for understanding Luther's view in contrast with other Christian thinkers.
The fact that this book had to be written it’s a bit sad. Anyone who believes Luther contended those outside of Christ are somehow saved, are either Woefully ignorant of Luther’s body of work, or willfully duplicitous. Even if Luther did contend for some sort of universalism in the large catechism. Page 93 through 105 are replete with citations were Luther argues against this point. There is one way of salvation, to Luther. Jesus Christ.
A great treatment of the subject at hand, but extremely narrow in scope. If you are interested specifically in Large Catechism II.66 interpretation, this is the most thorough treatment.