"Let mutual love continue. Do not neglect to show hospitality to strangers, for by doing that some have entertained angels without knowing it. Remember those who are in prison, as though you were in prison with them; those who are being tortured, as though you yourselves were being tortured."
It's a reminder of the story of Abraham told in Genesis where he shows hospitality to some strangers, who in the end turn out to be angels. The story contrasts with the response that is received in the city of Sodom whose inhabitants have forgotten their responsibility to care for the needy.
Putting aside for the moment the distraction of angelic existence, let us note the compelling incarnational calling in this passage. It's the 'golden rule' (Treat others as you would expect to be treated yourself) given in the form of some very specific examples: 'as though you were in prison...as though you yourselves were being tortured'. It's not surprising that these examples reflect the underside of society - Christians need to be in solidarity with those who are suffering.
Remember that all of us are made in the image of God and that when we respond compassionately to people in need, we are both responding to this image and simultaneously making God's presence on Earth a little clearer.