There is a reason that religions all emphasize sacrifice—whether the Christian sacrifice of Christ , or the Old Testament emphasis on Abraham or the pagan sacrifice of animals, or the Vedas which emphasize that the world began with Prajnapati's sacrifice of his body. I'm speaking very broadly here. But I don’t think that’s an accident: I think religion, aside from whether it expresses metaphysical truth, expresses anthropological reality: we have to give up something, even life itself, for the sake of the whole—the flow of Life. Herd animals will surround their young when a predator appears. Ethically, sacrifice reinforces the idea that as individuals we don't matter much: we matter in context—the context of the tribe, or of the herd, or of the cosmos, or the gods or God. The religion and the myths behind religion are supposed to help us accept that we're going to be broken down, our energy and spirit absorbed by our children and by the earth.
I think the 21st century so far, however, has been about the collective repression of the atavistic and spiritual need for sacrifice. Our civilization emphasizes permanent comfort and the intrinsic value of the individual; no one expects or wants to give up anything for anyone else. This century began with 9/11—ironically it began with the last public sacrifice, the last real vision of people putting others before themselves. Perversely, 9/11 ushered in an orgy of selfishness. Sacrifice, bizarrely, has become a kind of low-class marker. Sacrifice is for the rural poor, for the outmoded military family kids who signed up to fight in Iraq or Afghanistan, or now, it's for the poor suckers in Gaza and Ukraine—but it's not for us: meritocratic first world strivers. Modern people have better things to do: engage in transhumanist projects of optimizing their bodies and their youth; making as much money as possible; planning vacations for the sake of having something to put on Instagram; having kids that you don't really care about who are going to be raised by iPads; complaining when the Uber is late.