There are many adepts who approach the Knights and Masters of the Shadow side asking for guidance. "I wish to learn the way of the force, yet the light and dark confuse me. Which should I follow." In reply we tell them; the force does not control your destiny, you do. To follow one aspect of the force is to only try one flavour of ice cream, or to spend your whole life in one town. You cannot condemn something you have not tried, and you cannot possibly understand the Force from one perspective.
A shadow adept is trained to use the force as it should be used, we feel the ebb and flow, calling upon the vast energy when it is required. Many shadow adepts begin life as a light Jedi, training to see good in all. A light Jedi is selfless, thinking of others before themselves. This is a difficult task, light Jedi walk on a thin wire, to give in to their hate is to be all that is Dark. To devote themselves to the light is to deny all that they are. A Light Jedi Master has no life to themself, devoted to the light they cannot fall in love, or become angry when they are mistreated for these are selfish emotions.
Shadow adepts are 'not quite' fallen Light Jedi, they are Jedi who find a balance between their own needs and those of others. A shadow Jedi has the option of weighing up any situation they are in, using the force to achieve the best possible conclusion. If you have devoted yourself to the light think carefully about your choice. Do you want to give up all of your selfish emotions? Love, hate, anger, jealousy, pride, these are all selfish emotions which as a true follower of the light you would give up.
I remain in the shadows, helping others when I can, when I feel it necessary, when I want to. I help myself, and those I care about following an aspect of the force which allows me a choice over my actions.