Code Anyone?

I know some of you like to decode messages, so here's one to try. We are planning on giving it to James. I don't think it is too tough, but you can tell me what you think. Aaron and his dad send codes back and forth, and they have to follow one rule: It has to start with Dear Dad, and end with Love Aaron. This should make it pretty easy. Tell me if you solve it!

gdg udhg

cwlui vghhq ghui gqd ghui vghhq cwlui
cwlui vghhi ghui gqd ghui vghhi cwlui
grri ghui bcwlu kwlz cwlui vghhi ghui
grri cwlui bcwlu kwlz ghui vghhi cwlui
gldv qhwir vdk ghi qhkz cwlui gqd
ghui ghi cwlui d p’ghui, cwlui ghi ghui d p’l

qrudd hyro