Death Cannot Injure Those Who Have Received the Grace of Regeneration
But before a man can receive the commandment, it is necessary that he should live according to the flesh. But if once he has received the grace of regeneration, death shall not injure him, even if he should immediately depart from this life; “for to this end Christ both died, and rose, and revived, that He might be Lord both of the dead and the living;” nor shall death retain dominion over him for whom Christ freely died.
Source: The Enchiridion (New Advent)