Well, one example would be a fetus in its mother’s womb. When my babies were inside me, I was sustaining them, and their existence was dependent on mine, but at the same time, the babies were not me; they were independent beings even in their dependence on my sustenance. At least that is how I view unborn infants.
But for me, the fact that the cross is symbolic of anything depends on the historical, physical reality that generated the symbol in the first place. The forgiveness of our sins was accomplished by a physical death and resurrection and the revelation in Scripture that I give much greater priority to than logic-based metaphysical musings repeatedly hammers on the idea that Jesus died in a physical body and rose again with to physical new life, giving us the hope of our own physical resurrection in the New Creation.
No, I don’t grant that premise. I think the Incarnation as I understand it definitely depends on a physical reality that exists distinct from God’s Kingdom reality. My whole concept of the Kingdom is based on the idea of an in-breaking and eventual unification of God’s spiritual reality with our physical reality. That is the idea I see presented in Scripture and I’m not inclined to part with it just because a different conceptualization might stump an atheist. I’ll stick with special revelation on this one. 