The Rambam writes (Hilchot De'ot 6:3):
It is a mitzva for every Jew to love every other Jew like his own self... Therefore a person must praise his fellow Jew and be careful with his property the same way he is careful with his own property and desires to be treated respectfully. Whoever seeks honor through his neighbor's shame has no portion in the World-to-Come...

Sefer HaChinuch writes (Mitzva 243 [219]):
It is a mitzva to love every Jew deeply.

Our Sages said (Eliyahu Rabbah 28):
So said G-d to Israel: My children! Have I failed to give you anything? What do I ask of you? Only that you love, respect and revere one another, and that you avoid all sin, theft and unseemly behavior.

Our Sages also said (Avot 2:10):
Let your friend's honor be as dear to you as your own.

Hillel was once challenged by a gentile who asked to be converted under the condition that the Torah be explained to him while he stood on one foot. Hillel responded:
What is hateful to you, do not do to others. This is the whole Torah, the rest is commentary. Go and learn. Shabbath 31a, Babylonian Talmud

Love your fellow as yourself – Rabbi Akiva says this is a great principle of the Torah. Nedarim 9:4, Talmud Yerushalmi. Kedoshim 19:18, Torat Kohanim

---

Of this King Solomon said (Proverbs 24:10-12):
If you faint in the day of adversity, your srength is small indeed. If you forbear to rescue those taken to be killed and those ready to be slain, if you say, "We did not know," does He Who ponders the heart not consider it? And He Who keeps your soul, does He not know it? Shall He not render to every man according to his work?

Similarly, King Solomon said (Proverbs 21:13):
He who stops his ears at the cry of the poor shall also cry himself but shall not be answered.

Our Sages said (Shavuot 39a):
All of Israel (the Jewish People) are guarantors for one another.

When Rav Eliezer became ill (Berachot 28b):
His students came to visit him, and they said, "Master! Teach us how to live so we can merit the World-to-Come!" He replied, "Be careful to treat your fellow man with respect.

Whoever destroys one soul, it is as though he had destroyed the entire world. And whoever saves a life, it is as though he had saved the entire world. Jerusalem Talmud Sanhedrin 4:1 (22a)

Do not judge another man until you are in his place. Pirkei Avot 2:4

Where there are no men, strive to be a man! Pirkei Avot 2:5

---

The Golden Rule

The Golden Rule is the principle of treating others as you want to be treated. This principle is based on the words of the Torah, Vayikra (Leviticus) 19:18, and has been adopted by many religions and cultures all over the world. This principle may be stated in various forms:

• Treat other people as you would like other people to treat you
• Do not do to other people what you don't want other people do to you
• Do not treat others in ways that you would not like to be treated
• What you do to other people, other people will do to you