It’s not possible for all three of the following to be true.
- We are free.
- What we do matters.
- Everything will be all right in the end.
Proposition 2 implies that our actions can have permanent effects which can be either good or bad. If whatever we do can be undone, making the world the same as if we had never done it, then it doesn’t really matter what we do. Nor does it matter what we do if the final result of our actions is inevitably good (or inevitably bad). P2 means that it is possible for us to inflict serious, permanent irreversible damage.
And if we are free, it follows that at least some people some of the time will choose to inflict such damage. Therefore, everything will not be all right.
Actually, neither P2 nor P3 is a binary yes/no proposition; both admit of degrees. They are inversely related; as the truth-value of P2 approaches 1, that of P3 approaches 0. (This relation does not work the other way, though. A high P2 entails a low P3, but a low P3 does not entail a high P2. If everyone is inevitably doomed, for example, both propositions would be wholly false.)
If only minor damage is possible — if the worst we can do is to make things turn out “vey well” rather than “very very very well” in the end — then P3 is very nearly true and P2 is very nearly false.
If truly catastrophic damage is possible — if, for example, our actions could result in someone being consigned to eternal torture in hell rather than eternal bliss in heaven, then P2 is very true but P3 is emphatically false.
Perhaps P3 is necessarily false, human nature being what it is. We need to be free, and we need to be capable of doing things that matter — so if either of those conditions does not hold, things are therefore not all right.