In the wake of a number of unfortunate and shattering scandals, it is a particularly opportune time to remind ourselves of the traditional Jewish approach, guided by the wisdom of Chazal, as to how we should relate to others.
As opposed to the dangerously naive and delusional idea that "every Yid is a big tzadik", promoted by the TYH nation movement and others, our holy מסורה teaches us, כבדהו וחשדהו. Respect, but remain wary simultaneously.
In this vein, a story is related in מסכת דרך ארץ about how conducting himself in this matter saved רבי יהושע from being the victim of a cunning thief, as follows. A man came to R. Yehoshua, who gave him food, drink, and sleeping accommodations on his roof. During the night, the man stole utensils and turned to abscond with them by descending the ladder, whereupon he fell to the ground, sustaining serious injury. In the morning, when he was discovered in that state, R. Yehoshua rebuked him, saying empty one, did you not realize that we already were on guard against you from yesterday (removing your means of egress)? Whereupon R. Yehoshua taught that לעולם יהיו כל אדם בעיניך כליסטים, והוי מכבדם כרבן גמליאל. People (strangers, according to some) should be viewed as if they were ליסטים (thieves), while simultaneously treated with respect as befitting a great personality.
A further illuminating discussion of the issue can be seen here.
Once again, here we see a great illustration of the wisdom of Chazal, who taught us that לא עם הארץ חסיד, that to be a truly pious person, one must be learned.
May Hashem help us be truly learned and pious.