Some interesting thoughts on both red letter bibles and red letter Christians can be found here and here. Personally, I have to agree with Carson that these are foolishly printed bibles, well intentioned perhaps, but very foolish. There is no scriptural warrant to elevate or separate any part of scripture for any use. As 2 Timothy 3:16-17 reminds us, "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works." Thoughts anyone?