God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world. (Gal. 6:14)
Crucifixion means death – and so Paul is stating that when he was baptized into the death of Christ he was severed from this world or earthly realm. When Paul was joined to Christ in His death, he was severed from this earthly realm and made a citizen of the heavenlies.
Paul is referring to the fact that we are all born of this world as members of the Adam race. We are natural; of this earthly realm. Indeed, we are controlled by this realm – it is all we know. The Adam race is an earthly race that is very much at one with this
earthly realm. But when Christ died on the Cross and was raised from the dead, what emerged in that resurrection was a life that is not of this earthly realm. Indeed, it is a life that is completely severed from this earthly – in fact, has victory over it.
Resurrection life is not of this earthly realm. It is the life of Christ Himself. Thus, those in whom Christ dwells are not OF this world. They are of Him – and because we are planted in His death and resurrection we are severed from this earthly realm. We no longer belong to it and need not live controlled by it. This is what it means to, “walk in the Spirit.” We are no longer governed by the earthly, but only by Christ who is in us.