“We never have a full demonstration, although there is always an underlying reason for the truth, even if it is only perfectly understood by God, who alone penetrated the infinite series in one stroke of the mind.”

Source: What Men Live By (1881), Ch. XII
Context: And the angel's body was bared, and he was clothed in light so that eye could not look on him; and his voice grew louder, as though it came not from him but from heaven above. And the angel said:
I have learnt that all men live not by care for themselves, but by love.
It was not given to the mother to know what her children needed for their life. Nor was it given to the rich man to know what he himself needed. Nor is it given to any man to know whether, when evening comes, he will need boots for his body or slippers for his corpse.
I remained alive when I was a man, not by care of myself, but because love was present in a passer-by, and because he and his wife pitied and loved me. The orphans remained alive, not because of their mother's care, but because there was love in the heart of a woman a stranger to them, who pitied and loved them. And all men live not by the thought they spend on their own welfare, but because love exists in man.
I knew before that God gave life to men and desires that they should live; now I understood more than that.
I understood that God does not wish men to live apart, and therefore he does not reveal to them what each one needs for himself; but he wishes them to live united, and therefore reveals to each of them what is necessary for all.
I have now understood that though it seems to men that they live by care for themselves, in truth it is love alone by which they live. He who has love, is in God, and God is in him, for God is love.