17 But since in them there is that, which, by subsequent repentance, may be strengthened into faith; and by repentance strength is armed to virtue, which could not be armed if one should fall away through despair; if, hardly and cruelly separated from the Church, he should turn himself to Gentile ways and to worldly works, or, if rejected by the Church, he should pass over to heretics and schismatics; where, although he should afterwards be put to death on account of the name, still, being placed outside the Church, and divided from unity and from charity, he could not in his death be crowned.
And therefore it was decided, dearest brother, the case of each individual having been examined into, that the receivers of certificates should in the meantime be admitted, that those who had sacrificed should be assisted at death, because there is no confession in the place of the departed, nor can any one be constrained by us to repentance, if the fruit of repentance be taken away. If the battle should come first, strengthened by us, he will be found ready armed for the battle; but if sickness should press hard upon him before the battle, he departs with the consolation of peace and communion.
Source: The Epistles of Cyprian (New Advent)