If I recall correctly, the Buddha said that compassion and empathy are the nutrimental soil in which other liberating qualities can flourish. In fact, most religions and traditions emphasize it. But what is this, compassion?
As a good friend put it compassion is the sharing of suffering. That's why it is called com(lat. 'together')-passion('suffering'). When a friend suffers, I listen to him and give him a hand. Or when I need help, she's there for me. This is sharing.
However, compassion seems to be limited in its reach. It has suffering as a condition. Thus when we have only compassion, we might easily get attached to it. Compassion then becomes 'passion', empathy becomes apathy, oneself becomes distressed and weary.
For example, when someone does voluntary work only to distract him- or herself from problems at hand, one may be compassionate. But then one delights in the suffering of others, and sooner or later the problems catch up. Or for example, when one has so much compassion for other beings that they never get to stand on their own two feet.
Then what is called compassion here is actually a hindrance rather than a liberating act, it is tainted compassion. But when one is compassionate with discernment, then he or she helps others not in order to gain something from it, but simply because there is no other way. Then one is like a beautiful flower rising from the mud.
So sharing is not always sharing and giving is not always giving, but that which comes from a pure heart and an unconditional mind is the most precious gift. Thanks.