The sixth aliyos (sections) of both Acharei Mos and Kedoshim speak about forbidden relationships. Arayos is the failure to create a connection between two people. When man and woman come together positively, for the sake of a higher purpose, they bring the presence of Hashem between them. A true relationship is based on giving. If there is no giving, the land of Eretz Yisrael rejects this failure of relationship, and spits out those inhabitants.