The answer is: Philemon

A little book, only 25 verses, found just before Hebrews.

The Letter to Philemon might be small, but it's packed with powerful themes of forgiveness, loyalty, and social status. Paul wrote this letter while imprisoned, highlighting how even from behind bars, he was engaged in the work of nurturing relationships and advocating for fellow believers. Onesimus, the slave mentioned, had run away from Philemon—imagine the tension! This runaway slave turned into a useful companion for Paul, while fleeing from his previous life. It’s a twist of fate that speaks volumes about redemption.

What’s interesting is that Paul doesn’t just order Philemon to accept Onesimus back; instead, he appeals to Philemon’s sense of love and brotherhood, reflecting a revolutionary take on societal norms of the time. Slavery was a normal part of life in the Roman Empire, but Paul invites Philemon to see Onesimus not merely as property, but as ‘a beloved brother.’

Plus, here's a cool little trivia notion: despite the existence of slavery, early Christians strove toward principles of love and equality, hinting at the seeds of ethical change that would grow. The early church challenged the status quo subtly yet decisively. When Polycarp, an early martyr much later, noted he was called to “protect the lambs”—perhaps Paul was part of that foundation which would, in due time, underscore liberty. Philemon, therefore, isn’t just about individual storylines; it resonates with intersecting ideas of grace, social reform, and community among believers. Fascinating stuff!