Someone asked about the connection between the people we encounter each day and the wholesome and unwholesome systems operating within us.

Within the human body dwell three natures. During the periods when our merit is bearing fruit, we encounter good people around us — both new acquaintances and old, all cared for by the wholesome side. This merit is our own merit, which protects us and draws in good things and good people as a protective shield, keeping us within a suitable environment. A suitable environment is one that favors the wholesome taking root, because as long as conditions favor the wholesome arising, the wholesome draws in merit to correct, help, and bring about purity and liberation for us. So the two most important components are ourselves and our environment — both the surroundings and the people who favor the wholesome are drawn in through our own merit.

But during periods when we carry a difficult karmic result, the people around us may instead fall under the sway of the unwholesome. That karmic result draws people possessed by the unwholesome toward us. During such times, we need to make an aspiration to help transform the elements within their hearts — that is, to cultivate loving-kindness (mettā). Changing the elements within another person requires loving-kindness as the tool, so that it can clear the defilement from their heart. But if it can't be cleared away entirely, loving-kindness still serves as a protective shield, refining every particle of the surrounding atmosphere — ourselves, the people, and everything around us — toward cleanliness and purity, to the point that even weapons or poison cannot cause harm. Loving-kindness can transform the elements, clearing away what is unwholesome, and can change the heart and mind of someone under the unwholesome's influence.

That said, if the unwholesome within that person is powerful and firmly entrenched with strong intent, it becomes difficult to change. But if they hold no serious intention of vengeance or malice, loving-kindness can still help — it can lighten and even dissolve the unwholesome in their heart, at least the parts rooted in irritation or displeasure over a particular matter.