What are people for?
What people are for is, we believe, like guided missiles, to home in on God, God who is the one truth it is infinitely worth knowing, the possession of which you could never get tired of, like the water which if you have you can never thirst again, because your thirst is slaked forever and always. It’s this potentiality, this incredible possibility, of the knowledge of God of such a kind as even to be sharing in his nature, which Christianity holds out to people; and because of this potentiality every life, right up to the last, must be treated as precious. Its potentialities in all things the world cares about may be slight; but there is always the possibility of what it’s for. We can’t ever know that the time of possibility of gaining eternal life is over, however old, wretched, “useless” someone has become.
G. E. M. Anscombe, “Contraception and Chastity” [link]