Second point: Yes, it is possible. I can move a cart without being part of the cart. Without me, the cart is inert, with me, it moves. The cart does not become part of me nor do I become part of the cart. We remain ontologically distinct.
You might be able to move the cart without
being the cart itself, but you cannot move the cart without first
becoming a part of it. In the same way, God is part of us, and we are a part of God. In the same way, I am part of you and you are part of me. We collectively make up one body, just as all things make up the entirety of God.
The individual
parts of existence are a very real a part of God, but this does not mean the individual parts
are God. My being a part of you does not make me you, only a very real part of you and your reality.
Go back to Genesis and look to the fall of man. Adams sins effected us all, just as your sins and my sins effect us all. Like Wil suggested, we cannot harm others without harming ourselves. We are one, and are in this life together [as one].
The idea that we are separate from God, and separate from one another, causes us to be blind to the realities of life, just is it tends to make us selfish.
The sooner we realize that we are [one] and start learning from our mistakes and from the mistakes of others, and by putting others before ourselves, the sooner we (As a species) can begin the healing process (Collectively).
For as in one body we have many members, and the members do not all have the same function, 5 so we, though many, are one body in Christ, and individually members one of another.
Romans 12:4-5 (ESV)
GK