This quote by Alexander Pope suggests that a truly generous and deep friendship does not know any lukewarm or indifferent feelings. It either burns brightly with love or glows with resentment. Essentially, it suggests that in a genuine friendship, emotions are intense and extreme, rather than subdued or moderate.

The "burns with one love" part of the quote implies that in a real friendship, love is not divided or shared among many; it is focused and intense. It’s a strong, passionate love that consumes and engulfs, like a fire. It’s not a casual or flippant love, but one that is deeply felt and profoundly expressed.

The "glows with one resentment" part, on the other hand, suggests that when a friend is wronged, the other feels a shared sense of resentment or indignation. It’s not a petty or trivial resentment, but a glowing, simmering one that is felt deeply and personally. It’s a shared sense of injustice, a shared sense of being wronged.

Applying this idea to today’s world or personal development, it suggests that our friendships should not be shallow or superficial, but deep and meaningful. It encourages us to invest emotionally in our friendships, to feel deeply, to care deeply, and to share in each other’s joys and sorrows. It also suggests that we should stand up for our friends when they are wronged, to share in their sense of injustice, and to fight for them.

In terms of personal development, this quote can be seen as a call to cultivate deeper, more meaningful relationships. It encourages us to not settle for shallow or superficial friendships, but to seek out and nurture relationships that are based on mutual respect, shared values, and deep emotional connections. It also challenges us to be more empathetic, to feel more deeply, and to express our emotions more freely and openly.