Every human has a light AND a shadow side of their persona. For the health, balance and clarity of our psyche, I believe it is critical to face the shadow side of our persona.
What is the shadow side of our persona and what does it mean to "face" it? From my experience, it is the unconscious side of our persona where the shadow can manifest as selfishness, jealousy, aggression, abuse, suspicion, insensitivity or manipulation among other shadow aspects. I believe the important idea here is to face these shadow aspects in ourselves, to admit, on a conscious level that we have this side to us and not suppress or repress them, allowing them to manifest as unconscious passive/aggressive behavior. I am not saying to give them free reign but to see them for what they are: the darker side of our persona.
From my perception, we don't want play a game of hide and seek with our shadow side, we don't want to put a moral aspect on the shadow side saying it's good or bad. We look at this side of ourselves with compassion, understanding and acceptance that we are capable of shadow aspects and we must resolve to admit to ourselves that the shadow side of our nature is not exhibiting the highest aspects of our persona/psyche/ego as these unconscious tendencies can be quite destructive to ourselves and others. Why would we, as beings who move toward enlightenment, continue with shadow behavior? We can parent this side of our nature, knowing it is real, loving it, not judging it and then transmuting it into the light side of ourselves.
Here's an example: instead of continuing down the road of the shadow side of selfishness, that is, "for me only, for myself alone," we transmute that shadow aspect to "not for myself alone." We become aware that there is enough for everyone and there is no concept of a finite amount of anything. I will get mine and you will get yours as the size of the pie keeps expanding. You move out of lack consciousness into abundance consciousness. Out of the shadow, into the light.
Don't be afraid of your shadow side. Face it, admit these aspects that reside in you and then allow yourself to examine these aspects of yourself and realize them for what they are: unconscious urges that need to see the light of day within yourself so that you can transmute them as you understand that they are a lower aspects of your maturing soul. In my experience, a mature soul has moved out of its shadow.