Habeas Corpus means “you shall have the body”, our “we want the body” depending on which Perry Mason episode you prefer.  The idea was that police cannot just haul people off to some hidden place where they would never be seen again, but that they had the right to a public hearing and trial and to publicly confront their accusers.  That seems to be a quaint and pathetic concept in America to today but it used to be  big deal.  Anyway Luther used something like this expressing when he thought about the glory of the Christmas story.  The more Luther meditated on the “enfleshment” of Christ and what it meant in terms of our freedom from sin death and hell, he was worked into an ecstasy of gratitude and stunned by the absolute immensity of what that simple Christmas story really meant.  He was angry and depressed as the years went on that people didn’t “die for joy” when they contemplated the birth of Christ among men.  Making a long story short, because the Son of God was conceived and born precisely that He might have human flesh and be able to die, we have the knowledge that our bodies, freed from sin because Christ “took them away” , will live forever. Luther was frustrated that, in his view more and more people looked to Christ as a moral exemplar and new Law giver, and that they emphasized eternal life at all they did it for the soul.  The body seemed to be an husk that could be left behind.  For Luther, if that was all the Christmas story was about, he prefered to trust in law books and pagan philosophy.  He is quoted by some as saying that he did not just want the immortal soul -“I also want the body.”