Some history for those of you that must must know!
This is known as a
Caesar cipher. In short, all the letters are shifted in a direction. Here, the alphabet is shifted three letters to the right (note the solitary "d" in the message, a good place to assume it is either an "a" or an "i").
Code:
EPHL HLYE K VKCLKD VHJPCD. EPHL IYC
LHEL HY NDIYE IN FIG CWCY DHOPE YIB.
TCXDKL KDC LEDHJCM EI JDIECVE EPCZLCSWCL
NDIZ JDCMKEIDL. TCXDKL DGY AGHVRSF.
This one isn't a Caesar cipher. However, it is based off of a pattern that we use all the time.