How are we one with Christ according to the marriage analogy?

Les explains the marriage analogy: as husband and wife become one, so you and I and Christ are one. On that basis, if any man be in Christ, he is a new man; the old cannot just be fixed up. Les also uses the dead battery illustration: when Adam sinned, his soul became a sin nature, his spirit died, and he lost fellowship with his Creator. That dead spirit is like a dead battery in a car. Cleaning and shining the old battery does nothing; turning the key gives nothing because it is still dead. Only an outside source—a jump or generated energy—brings power. Spiritually, we have been dead as a result of Adam’s sin, so it takes an outside source of power, the power of God, to energize our spirit. When He energizes the spirit, He makes us a new person, or a new creation.