Awaken the Dead (2007)

When the DEAD walk the earth, there's no place for a man of peace.

Two down and out strangers are brought together by mysterious letters into a safe house as the world around them is infected by an experimental virus that transforms the living into the living dead. She is a former prostitute hiding from the world. He is a former assassin turned priest who has renounced violence. Together they must unravel the mystery of the letters if they hope to survive.