Pierre Teilhard De Chardin

Oneness is the experience of commonality with others. It is based on an awareness of a common essence, that is our life energy.

A sense of oneness is a characteristic of the state of higher consciousness. In this state we become aware of the single ground from which everything emerges, physical and non-physical. The distinctions between things become secondary to their oneness.

-In oneness, we retain our individuality. Our higher consciousness grants us a knowledge of oneness with spirit but also a retention of our individuality within that oneness, our true self. The awareness of this relationship allows our true self to transcend the ego knowing that we are more than the ego while still acknowledging the ego within its own realm and with its own valid functions.
-We expand our sense of identity to groups. As Sigmund Freud said in a letter to Albert Einstein, "The love of country has succeeded at bridging people at the national level. The great new historical challenge is the development of love among all the earth's inhabitants, and for the earth itself." In other words, we can love our group without hating other groups. We can expand our sense of identity, and a type of oneness, to include ourselves, our family, our community, our nation, our humanity and the life energy that is us all.