If I recall rightly, Aquinas had the somewhat strange idea that those people alive at the Second Coming would still die, though only for a moment (using "moment" non-technically). This is an odd position, and one might think it results from an overreading of Scriptural claims that all people die. But consider this argument:
- (Consummated) Christian marriage only ends with death.
- After the Last Judgment, there are no marriages.
- All people will be alive after the Second Coming.
- Therefore, all Christian married couples who are alive just before the time of the Second Coming will experience the death of at least one of the spouses by the time the Last Judgment is complete.
- If (4), then all people on earth who are alive just before the Second Coming will die by the time the Last Judgment is complete.
- Hence, all people on earth who are alive just before the Second Coming will die by the time the Last Judgment is complete.
One might challenge (1) as follows. Christian marriage ends with death or with the transformation of the body at the time of the general resurrection. We do not know what that transformation involves, but perhaps it is radical enough to make marriage no longer fitting.