As followers of Jesus, we are encouraged to be generous and giving. Hospitality is part of that. Sometimes when we show kindness to others, we will never know the affect of our actions. As an encouragement in being generous and giving, Paul writes, “Do not forget to entertain strangers, for by so doing some people have entertained angels without knowing it.”
This is an interesting thought. Of course, we would never know if it were to happen.
However, the Bible provides a story that confirms this idea of serving angels. Three men come to visit Abraham. He offers them food and respite. Somehow he realizes that one of them is God (likely Jesus), but it is not until later that we learn the other two are angels. No indication is given that Abraham ever comprehends the true identity of the other two visitors.
The two men (angels) leave, going on to Sodom to visit Abraham’s nephew, Lot. He, likewise, offers generous hospitality to them, even to the point of begging. There is no hint that Lot ever realizes the men are angels, either. Even so, they save Lot twice, first from the men of the town and later from the destruction of Sodom.
Certainly we should be diligent in entertaining strangers — we’ll never know what might happen.