How we cite our quotes:
You cannot die because you belong to the cruciform and follow the way of the cross (1.339)
Duré does follow the way of the cross, Catholicism, and he's about to see certain aspect of his religion become way too real. That'll fix his doubts—but will it save him? Or destroy him?
All die the true death [...] except the Three Score and Ten (1.510)
Well, maybe. We're thinking that the Bikura might have died the true death when Orlandi nuked them. Can the cruciform withstand a nuclear explosion?
The Bikura have realized the human dream of immortality and have paid for it with their humanity and their immortal souls. (1.646)
Duré believes that losing your individuality and identity is the same as eternal damnation, so he decides to kill himself to avoid the same fate. Death is his only release.