"Saying Liebe is an emotion is like saying water is an atom."
Liebe is made up of a number of different kinds of emotions in different amounts, between me and Caramae there is a mutual trust, compassion, lust, and other emotions. Between me and my brother, there is respect for opinions and ideals, respect for skills, and a history together.
Du see, Liebe is such a broad term, and a hard one to define, it is because it is a combination of different kinds of emotions, therefore making different kinds of love. The Liebe I have for my girlfriend is classified as sexual love, but it isn't pure lust. The Liebe I have for my brother is platonic, and includes no lust, but it is largely a mutual respect.