A Word to the Wise

Decode this message by writing in the letter of the alphabet that comes before each letter given below.

“__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __”
M P T U U J N F J T O F W F S G P V O E B H B J O

__ __ __ __ __ __ __ __ __ __ __ __ __ __ __ __
C F O K B N J O G S B O L M J O

Answer: