There is a Sufi saying, "to be in the world but not of it." This phrase can have many meanings. The meaning depends on the situation and on your own development and capacity for understanding. To be "in the world but not of it" is a matter of orientation. I will talk about some of the meanings of this phrase so you'll have a better understanding of what we are doing here.
When a baby is born, it is pretty much all essence, or pure being. Its essence is not, of course, the same as the essence of a developed or realized adult. It is a baby's essence--nondifferentiated, all in a big bundle. As the child grows, the personality starts developing as a result of interactions with the environment and especially with the parents. Since most parents are identified with their personalities and not with their essence, they do not recognize or encourage the essence of the child. So, after a few years, the essence is in fact forgotten, and instead of essence, personality develops. Essence is replaced with various identifications. The child identifies with one or the other parent, this or that experience, and with all kinds of notions about itself. As the child grows up, these identifications, experiences and notions become consolidated and structured as its personality. The child, and later, the adult, believes this structure is its true self.
However the essence was there to begin with, and is still there. Although it was not seen, not recognized and even rejected and hurt in many ways, it is still there. In order to protect itself, it has gone underground, undercover. The cover is the personality.
There is nothing bad about having a personality. You have to have one. You couldn't survive without it. However, if you take the personality to be who you truly are, then you are distorting reality , because you are not your personality. The personality is composed of experiences of the past, of ideas, of notions, of identifications. You have the potential to develop a real individuality, the personal essence, which is different from the personality that covers the loss of the essence. But this potential is usually taken over by what we call our ego, our own acquired sense of identity.
If a person believes himself to be the ego, the identifications, ideas and past experiences, then he is said to be "not in the world, but of it." He is not aware of who he really is, of his essence. This is difficult to understand unless we are aware of our own essence at least some of the time.
So the ego, or the sense of ego identity, takes the place of what we call the real identity; and the personality as a whole takes the place of essence. The personality is a substitute, an imposter. However, the world is just the world. It is the same for both essence and personality. What exists, exists. But the way the world is seen is different. A person who is "not in the world, but of it," is oriented toward the personality instead of toward essence.
[From: Diamond Heart, Book One]