וְאֵין נֶאֱמָן אָדָם עַל יְדֵי עַצְמוֹ... אֵין אָדָם מֵעִיד עַל יְדֵי עַצְמוֹ:
But no man is trustworthy about himself...No man is believed [to testify] about himself.
Rav Menashe said to you: I am speaking even according to the Rabbis. And the rationale of the Rabbis here is in accordance with Rava, as Rava said: a person is his own relative. And, a person does not make himself wicked.
Akeidat Yitzchak, 11:73 (Eliyahu Monk)
Hitnachmut, regrets, is not a change of viewpoint when the premise for that viewpoint has remained constant. Rather, it is a re-consideration of one's plans and attitudes based on a changed set of circumstances. If a person vows to do good to a friend because he has faith in that friend's loyalty, and the friend turns into an enemy, then the cancellation of his vow to do good does not constitute a change of mind, a breaking of one's promise. Rather, it is an admission that one had erred in one's assessment of the facts which one's promise had been based on. A changed attitude then becomes an act of wisdom, a rejection of foolishness.
Rabbi Jonathan Sacks, Leadership and Loyalty
The Hebrew word emunah is usually translated as "faith," and that is what it came to mean in the Middle Ages. But in biblical Hebrew it is better translated as "faithfulness, reliability, loyalty." It means not walking away from the other party when times are tough. It is a key covenantal virtue. There are people with great gifts, intellectual and sometimes even spiritual, who nonetheless fail to achieve what they might have done. They lack the basic moral qualities of integrity, honesty, humility, and above all, loyalty. What they do, they do brilliantly. But often they do the wrong things. Conscious of their unusual endowments, they tend to look down on others. They give way to pride, arrogance, and a belief that they can somehow get away with great crimes. Balaam is the classic example, and the fact that he planned to entice the Israelites into sin even after he knew that Gd was on their side is a measure of how the greatest can sometimes fall to become the lowest of the low. Those who are loyal to other people find that other people are loyal to them. Those who are disloyal are eventually distrusted, and lose whatever authority they might once have had. Leadership without loyalty is not leadership. Skills alone cannot substitute for the moral qualities that make people follow those who demonstrate them. We follow those we trust, because they have acted so as to earn our trust. That was what made Moses the great leader Balaam might have been but never was. Always be loyal to the people you lead.
כל ישראל והנלוים אליהם הרי הם כאחים שנאמר בנים אתם לה׳ אלקיכם אם לא ירחם האח על אחיו מי ירחם עליו?
Rambam, Matnot Aniyim 9:3
All of Israel and all who are attached to them are like brothers as it says "Ye are the children of the LORD your God" and if a brother will not have compassion for his brother, who will have compassion for him?