Think about this for a minute: you are being hospitable to someone and (unknowingly) you are treating a person that might really be an angel. Most of the time, you can tell who someone is. But here, the author is saying that an angel will sometimes willingly withhold their identity. Why is this important to us? Sam Storms tells us why in his blog article:
“This exhortation carried a lot more force back in the first century than it does for us today. In the first century world there weren’t dozens if not hundreds of hotels scattered throughout their large cities. People then were far more dependent on the generosity and hospitality of others than they are now. So he’s not really talking about whether or not in our day we should consistently invite people over for dinner. That is still an important issue, but it would more likely fall under the heading of the exhortation regarding brotherly love…
“What’s of real interest, though, is the reason given why you should be hospitable, when you can, to strangers who might cross your path. He mentions that in times past certain people opened their homes (tents!) and were generous with their food and never knew that the so-called “people” whom they served were in fact angels.
“He is probably referring to the incident in Genesis 18 where Abraham received three strangers into his tent and gave them water and bread and washed their feet. He had no idea that two of them were angels in human form and the third was probably a pre-incarnate manifestation of the Son of God (what theologians often refer to as “Christophanies”). The two angels later visited the city of Sodom and were received by Lot. You may recall that the homosexual community in Sodom found out about these two visitors and demanded that Lot turn them over so that they could have sexual relations with them! These two angels, posing as men, in turn afflicted the homosexual mob with blindness and later led Lot and his family out of the city just before God destroyed it with fire and brimstone…
“If you ask me why God would do this, I can only answer by pointing to the many biblical texts which speak of angels being sent to communicate God’s will to his people or being sent to serve, protect, and minister to the elect or being dispatched to accomplish some other aspect of God’s purposes on the earth. We may never know for certain why they appear, but I see no reason to dismiss the possibility that they can. So be hospitable!
“By the way, if you are wondering why people would interpret a passage such as this in a way that either reduces or rules out the possibility that angels might still visit us today, it usually goes hand in hand with the doctrine of cessationism. That is to say, some who reject the contemporary validity of the more overtly supernatural spiritual gifts are equally uncomfortable with the idea that angels might actually interact with humans. They typically are people who, while not denying altogether the possibility of such encounters, minimize the miraculous and are more inclined to supply a natural or material explanation for much of what occurs in the life of God’s people.
“Whereas some fall into the extreme of finding a demon behind every bush, others are no less inclined to find an angel around every corner! The fact is, such angelic visitations are miraculous and for that reason rare. So, let’s be careful lest we drift into a super-supernaturalism (as J. I. Packer describes it) at one end of the spectrum or an overly cynical naturalism at the other.”1