Again, we are told that in time of persecution certain holy women, in order to escape the pursuers who threatened their virtue, threw themselves into a river that they knew would bear them away, and so met their end; in the Catholic Church, their tombs are venerated like those of martyrs. Regarding these women I will not venture to pronounce hasty judgment. Whether, on the strength of certain thoroughly reliable testimony, divine authority inspired the Church thus to honor their memory, I cannot say. It may be so. For, what if those holy women acted, not through human deception, but at God’s bidding; not in error, but under obedience? In the case of Samson, we must believe that this was so.
When God commands and makes His command known beyond doubt, who can call obedience an offence? Who will reproach such pious homage paid to God? But, no one who decides to sacrifice a son to God is free from guilt, just because Abraham did so and was commended for it. When a soldier kills a man in obedience to the authority under which he is lawfully commissioned, no law of his country holds him guilty of murder. In fact, unless he does it, he is guilty of desertion and disobedience. On the other hand, if he killed on his own impulse and authority, he would have incurred the guilt of murder. The same law which punishes him if he acts without orders will punish him unless he obeys orders.
This is one’s duty when a general commands; it is much more so when God commands! Hence, one who knows that he is forbidden to kill himself may yet do so if he is ordered by one whose orders he dare not disobey. Only, let him make certain that there is no doubt about the divine command. What goes on in one’s conscience we know only from its manifestations; we presume not to judge its secrets that remain hidden. ‘For what man knoweth the things of a man but the spirit of a man that is in him?’
This we declare and affirm and emphatically accept as true: No man may inflict death upon himself at will merely to escape from temporal difficulties—for this is but to plunge into those which are everlasting; no man may do so even on account of another’s sins, fearing they may lead to a sin of one’s own—for we are not sullied by others’ sins; no man may do so on account of past sins—for to expiate them by penance we need life all the more; no one may end his own life out of a desire to attain a better life which he hopes for after death, because a better life after death is not for those who perish by their own hand.
Augustine of Hippo, The City of God