The answer is: Bible

Rom 12:9

In Romans 12:9, we catch a glimpse of Paul's vision for a community rooted in authentic love. "Love must be sincere," lays the groundwork—it’s about real feelings and actions rather than just lip service. It's invigorating to think about how much potential there is when relationships are built on genuine affection. Trust, community spirit, and compassion thrive where such love flourishes.

The second part—“Hate what is evil; cling to what is good”—sounds simple but is profound in translation. The original Greek uses "agape" (the highest form of love) and juxtaposes love with hatred towards evil, showcasing a moral responsibility. The transition from personal feelings to a communal ethical stance encourages individuals not only to pursue personal goodness but to actively oppose harm in their communities.

Here’s a fun nugget: in the larger context of the Book of Romans, Paul highlights the contrasts in life as essential; light versus darkness, good versus evil. It's the human experience of grappling with these oppositions.

An interesting parallel you might enjoy is where this concept echoes throughout many literary and philosophical teachings, from ancient works to modern self-help concepts—demonstrating universal principles of integrity and morality.

So, when you embrace the essence of true love, you take a stand for good. This elaboration becomes a guiding principle, illuminating pathways toward inner peace and communal harmony. Isn’t it fascinating how two thousand years ago, messages about love and doing good resonate so vibrantly today?