“Luther’s insults don’t change the fact that he added a word that wasn’t there.”
He added it to make the sentence GOOD GERMAN. When you translate, you always change it some because you are changing languages. If you seek what is now called “dynamic equivalence”, then you add and subtract more, because you are trying to translate the thought instead of just the words.
A word for word translation isn’t generally considered very readable, certainly not for longer passages. For example:
“14 `And as Moses did lift up the serpent in the wilderness, so it behoveth the Son of Man to be lifted up,
15 that every one who is believing in him may not perish, but may have life age-during,
16 for God did so love the world, that His Son — the only begotten — He gave, that every one who is believing in him may not perish, but may have life age-during.
17 For God did not send His Son to the world that he may judge the world, but that the world may be saved through him;
18 he who is believing in him is not judged, but he who is not believing hath been judged already, because he hath not believed in the name of the only begotten Son of God.”
While reasonably literal, it is not truly literal - and yet it is awkward to read in English. As a study tool, it is great. As a devotional bible, it is lacking.
“I had not read the cites from Luther you provided, but it is consistent with the worst I had read of the man.”
I gather, then, you haven’t bothered to read Sir Thomas More either. It was the style of the day, regardless of which side one supports. If you think the Catholics of the day dripped with politeness, you would be sadly mistaken.