We are made of stuff like molecules, cells etc. You could argue that your cells are those produced by YOUR DNA while mine are made of MY DNA. But how do you claim ownership of something like DNA, which is a mere arrangement of particles, which neither did you choose, nor did you manufacture. All DNA does is describe how to make cells of "YOUR Body". But with genetic engineering, it is now possible to manufacture babies with desirable traits and remove undesirable ones. So if someone does that procedure to your baby, is it suddenly not your baby anymore? Where do you draw the line between what is considered your DNA, and what is considered random mutation? Our DNA constantly changes in the course of our lives, and the DNA we die with isn't the DNA we were born with. Yet the "I AM" that rises in the course of our lives stays fairly persistent. The only scientific conclusion is that this "I AM" cannot be true, you are not true. If every thing beneath your feet changes, but you remain, either you were never there, or you are something entirely else.

If I'm short of say a molecule X, I can just take one from you. You won't change, neither will I. Yet if we do this process carefully enough, I can completely replace your body with mine and my body with yours, adding and removing extra molecules where needed, and you won't change neither will I. Ultimately, this is the exact process that happens everyday. We buy our molecules from the supermarket, cook and ingest them, and they make us what we will be. So when we die, what really died? What lived? Do you see what I'm getting at? Rationally it doesn't make sense why one should work against death. What is the necessity of keeping those food molecules in my body? If my identity cannot be encoded in any molecule, then what is left is the current arrangement of particles right now in my body. Am I the particle arrangement?