The Lovers is about our power to make independent choices. When we reach sexual maturity our sexual urge drives us to break away from the family unit. This then pushes us on to form intimate relationships with other people and it is through that experience that we find unity with someone else and capture a deeper meaning of life.
In the biblical sense, Adam (Yang) was ruled by reason, whereas Eve (Yin) was controlled by desire. In this context, reason controls and contains, whereas passion tends to break down all limits. The mountain in the card represents raising our senses through passion and desire, sexual passion allows us to transcend isolation momentarily. The lovers often signifies choice between something that is respectable and a little dull, or something that is desired but seen as morally improper.
In a reading, the Lovers represents a sexual relationship but it can often be about making important independent choices, so that we can find our own way in life.