People undoubtedly have looked on me as pretty gullible over the years, welcoming seemingly random people into my life and my home (and indeed, it has perhaps been more out of gullibility than out of noble Christian principles). Yet, I feel I fall GREATLY short of what a true Christian should do.
Here's what St. Benedict of Nursia had to say in the Sixth Century in the Rule of Benedict, the document which to this day governs how Benedictine and Cistercian monasteries operate. Much of it could be applied to non-monastics, as well. I'm not sure how I would feel about making guests pray with me, or washing their feet, but the principle is simple - treat them well, as if they were your brothers or sisters. (Because they are.)
Chapter 53: On the Reception of Guests
Let all guests who arrive be received like Christ, for He is going to say, "I came as a guest, and you received Me" (Matt. 25:35). And to all let due honor be shown, especially to the domestics of the faith and to pilgrims.
As soon as a guest is announced, therefore, let the Superior or the brethren meet him with all charitable service. And first of all let them pray together, and then exchange the kiss of peace. For the kiss of peace should not be offered until after the prayers have been said, on account of the devil's deceptions.
In the salutation of all guests, whether arriving or departing, let all humility be shown. Let the head be bowed or the whole body prostrated on the ground in adoration of Christ, who indeed is received in their persons.
After the guests have been received and taken to prayer, let the Superior or someone appointed by him sit with them. Let the divine law be read before the guest for his edification, and then let all kindness be shown him. The Superior shall break his fast for the sake of a guest, unless it happens to be a principal fast day which may not be violated. The brethren, however, shall observe the customary fasts. Let the Abbot give the guests water for their hands; and let both Abbot and community wash the feet of all guests. After the washing of the feet let them say this verse: "We have received Your mercy, O God, in the midst of Your temple" (Ps.47:10).
In the reception of the poor and of pilgrims the greatest care and solicitude should be shown, because it is especially in them that Christ is received; for as far as the rich are concerned, the very fear which they inspire wins respect for them.