Hence we must distinguish two kinds of envy, one evil and the other holy. The evil kind is that which envies and repines at the worldly goods possessed by others on this earth. But holy envy, so far from wishing to be like, rather compassionates the great ones of the world, who live in the midst of honors and earthly pleasures. She seeks and desires God alone, and has no other aim besides that of loving him as much as she can; and therefore she has a pious envy of those who love him more than she does, for she would, if possible, surpass the very seraphim in loving him.
--St. Alphonsus Liguori, The Holy Eucharist