From Time Regained (1931), by Marcel Proust.

We can, perhaps, attach every creature who has caused us unhappiness to a divinity of which she is only the most fragmentary reflection, a divinity the contemplation of whom in the realm of idea will give us immediate happiness instead of our former pain. The whole art of living is to regard people who cause us suffering as, in a degree, enabling us to accept its divine form and thus to populate our daily life with divinities.