Fake Luther quotes are not as numerous as fake Augustine ones, but they are pretty close. Justin Taylor summarizes 6 quotes that Martin Luther never said:
1. If I believed the world were to end tomorrow, I would still plant a tree today.
2. The maid who sweeps her kitchen is doing the will of God just as much as the monk who prays—not because she may sing a Christian hymn as she sweeps but because God loves clean floors. The Christian shoemaker does his Christian duty not by putting little crosses on the shoes, but by making good shoes, because God is interested in good craftsmanship.
3.If I profess with the loudest voice and clearest exposition every portion of the Word of God except precisely that little point which the world and the devil are at that moment attacking, I am not confessing Christ, however boldly I may be professing Him. Where the battle rages there the loyalty of the soldier is proved; and to be steady on all the battle front besides, is mere flight and disgrace if he flinches at that point.
4. I’d rather be ruled by a wise Turk than by a foolish Christian.
5. Justification is the article by which the church stands and falls.
6. Here I stand; I can do no other.
Some of these are close to something Luther said but not quite. Others are sheer fable. I would love to know more about the last one, of course, since it does appear to have a very early origin. I suspect there’s more to the story there.