LEV450 If you see a man saying or doing something for which he may be judged either favorably or unfavorably--if he is a God-fearing man, you are obliged to judge him favorably in keeping with the truth, even if the indications are much more for an unfavorable than for a favorable judgment. And if he is in the middle range, generally keeping himself from sin, but sometimes stumbling into it, you should put aside the doubt and judge him favorably. Our Rabbis of blessed memory have said [Shabbos 127b]: "One who judges others on the scale of merit will be judged by the Almighty on the scale of merit." And this is a positive commandment of the Torah, as it is written [this verse]: "In righteousness shall you judge your neighbor." And if the indications are for an unfavorable judgment, let the matter be doubtful in your eyes and do not judge him unfavorably. If most of the man's actions and words, however, are evil, and you know that there is no fear of the Exalted One in his heart, then an unfavorable judgment is to be placed upon his deeds and words.