Ivan’s Thesis: Immortality is necessary for morality.
1.) No immortality, no God. “Immortality” means any eschatological renewal and judgment. Absent such an eschatological reckoning, good does not ultimately triumph and evil is not decisively overcome. Thus, the argument from evil is sound and God does not exist.
2.) No God, nothing sacred. God is the paradigm and fulness of the sacred and any notion of the sacred that might remain or be appealed to in an atheist culture is living on borrowed time.
3.) Nothing sacred, nothing inviolable or out of bounds. The sacred is what is set aside and removed from profane use and so marks a limit beyond which man absolutely cannot go. When these limits are sacred, however, they can be beautiful, ennobling, and conduits of transcendence. We may not be able to enter the sacred space but it is still a place we can be next to. When we lose the sacred, the limits on action become mere taboos: speech codes, groupthink, hypersensitivity, totalitarian micromanagement, moral posturing and elitism, etc. These can be enforced for a generation or two but generate resentment and disgust leading to an inevitable backlash which takes its greatest joy in the transgression of the secular ersatz “sacred”.
With nothing out of bounds the secular world is powerless before the demands of power and the hard cases generated by moral absolutes. When what we want and the demands of real life run into the absolutes that are no longer taken as sacred, the absolute will give way and soften. To some extent this will happen even with the sacred, but the backlash against the ersatz secular sacred makes any absolute far less stable and perhaps even ultimately not worth the trouble. Any things or groups defended by taboos will probably end up worse off than if they had been left to fend for themselves.
And so the pop-summary of Ivan’s thesis that without God all is permitted can be defended as a claim about the sacred. Without the sacred, we have nothing sturdy enough to stand up to power and concupiscence, to give meaning to hard cases, or to compensate for the resentment that arises from ruling things outside the pale. Even where secular and purely rational morality defends real goods, they aren’t doing those goods any favors.