G-d instructed Moses to tell the Jewish people, "You must judge your fellow righteousness."
Vayikra 19:15
Our Sages exhort us to "be extremely humble in relation to every person," i.e., to consider ourselves less worthy than anyone else. Yet, objectively speaking, how can we consider ourselves less meritorious than those who appear to be unworthy of our respect?
The answer is by keeping in mind the Sages' teaching: "Do not judge your fellow until you reach his place." In other words, we all have challenges; the fact that we do not succumb to a particular temptation while another person does, does not make us superior to him. Who can measure the effect of his upbringing, environment, or inborn character weakness against the temptation he faces?
By judging our fellows favorable -- or better yet, by not judging them at all -- we can both cultivate our own humility more effectively and allow our fellows' positive traits to manifest themselves unhindered.
From Kehot's
Daily Wisdom #2