Let brotherly love continue. Do not neglect to show hospitality to strangers, for thereby some have entertained angels unawares. (Hebrews 13:1-2)
“Moreover, Christians’ sense of cultural alienation was often expressed through identification with exiles and refugees. Because Christians were at times under threat from civil authorities, the act of harboring refugees who were brothers and sisters in Christ became imperative. Sheltering strangers was essential to the survival of Christianity in a hostile empire. Christians became well-known within the larger culture for their practices of hospitality and were often cited as examples of morality on this account. … It is not a far step from understanding oneself to be a stranger in the world to identifying with other political, economic and social strangers, and vice versa.” (Amy Oden in ANCIENT AND POSTMODERN CHRISTIANITY, p 43).
“For Christians are not distinguished from the rest of humanity by country, language, or custom. … They live in their own countries, but only as nonresidents; they participate in everything as citizens, and endure everything as foreigners. Every foreign country is their fatherland, and every fatherland is foreign.” (Letter to Diognetus)