I just love the name Luther. It's handsome and dignified, and familiar but not common. Plus, it fits it perfectly with all the other popular -er boy names.
My 10 month old son's name is Luther Wolf. We loved the name because:
1. Uncommon but well known
2. Easy to spell and pronounce
3. My hubby has German heritage
4. Like the meaning of the name
5. Has a lot of good associations
6. Sounds badass and masculine, lol
I love the name, and I think using Luther as a first name for one child while using Luke as a middle name for another is fine.
@stripedsocks - just curious why you think it is creepy and ominous? I feel a little insulted.