Chip Ingram writes about the difference in Love, Sex and Lasting Relationships (great read).
A brief synopsis can be found at the following link:
It’s easy to go blindly into a relationship. It’s also easy to operate solely from infatuation and not develop true lasting love with another. When the infatuation “runs out” (in 6-18 months), someone might believe that he/she is no longer “in love.”
Learn the difference and save yourself some hurt.