The way to successfully integrate the spiritual and material is through seeing that they are in fact not different from each other, but are reflections of the one reality, the one divine consciousness, or energy, that underlies all creation. The more clearly you see this, the easier it is to walk in the world with balance.
This is where the core insight comes in. The core insight, which has its roots in a number of enlightenment teachings, of both the East and the West, is the fundamental perspective behind the inner path. It is the knowledge that heals personal conflict, liberates you from fear and limitation, and allows you to fulfill your unique potential--to bloom as the beautiful, conscious, and creative person you really are.
Every person I have ever met who has found genuine inner peace and freedom (and more and more of us are coming into this), has arrived at this understanding, this jewel of wisdom that I call the core insight. This is true whether they discovered it through a formal spiritual practice, contact with an awakened teacher or person, or through their own inquiry and investigation.