Philemon

Philemon is Paul's shortest letter — 25 verses — and his most personal. Onesimus, Philemon's slave, had run away and somehow met Paul in prison and become a Christian. The letter asks Philemon to receive him back "no longer as a slave, but... as a beloved brother". Paul does not give an order, though he makes clear he could; he appeals. And he offers to pay any loss out of his own pocket. The text does not write a treatise on slavery, but it plants an idea that corrodes it from within: two men in opposite legal positions become brothers. It is a good read for anyone wanting to see how convictions change concrete relationships.