Here are 3 different sayings encoded using the same code:
G JISL MC RGDYGS MC TMSDBYZMKGKX ABDDBKV.
-- ZOIAIZ AGKJIS MS GSDOMSX RNKPBVV
RB TGKBCNA MC KBGLISP OBGADO RMMJV, XMN YIPOD LIB MC G YIVZKISD.
-- YGKJ DWGIS
F: WOX LM WGVZV ZAGX PMAC ?
G: VM DOBX TGS LKBVV AIJB ZIYZV.
I give up!