The Christian in the world

Jaques Ellul wrote:

"The Bible tells us that the Christian is in the world, and that there he must remain. The Christian has not been created in order to separate himself from, or live aloof from the world. ...if the Christian is necessarily in the world, he is not of it. This means that his thought, his life, and his heart are not controlled by the world, and do not depend upon the world, for they belong to another Master. Thus, since he belongs to another Master, the Christian has been sent into this world by this Master, and his communion with his Master remains unbroken, in spite of the 'world' in which he has to live.
"...the Christian finds that he is not confronted by the material forces of the world but by its spiritual reality. Because he is in communion with Jesus Christ he has to fight not against flesh and blood but against 'the principalities, against the powers, against the world-rulers of this darkness.' At the same time this communion assures him that he does not belong to the world, that he is free from the fatality of the world which is moving towards death, and, as a result of this liberation by grace, he can fight against the spiritual realities of the world."

More can be found here.