Your soul is your life. Everything else is a fiction -- a mind game in authenticity. Without nourishing your own soul, you can't nourish the world; you can't give what you don't have. As your soul grows, however, it emanates invisibly and involuntarily the light which it has received.
I think that those who serve most potently, work on levels of consciousness that have to do with radiating love — maybe God's love... It is important that you have a brain and use it, but that is secondary. The basic premise is that you allow something to come through you. Then you use your intelligence to give your heart's work discipline and logic. But the transformative energy, that which can change events, that heals, that helps, that serves, comes from somewhere deep inside.