Can I read Passion before reading Fallen by Lauren Kate?

My mother did a great thing for me with the best intentions, since I am sick and cannot leave my bed for a while, she went and brought me books from my booklist. The problem she brought Passion by Lauren Kate and it is the third in the saga, and I have not read the first book, they told my mother at BN (Barnes and Noble) that is was a prequel and can be read without reading the first, is this true or should I wait and buy Fallen and Torment first?