2. Rabbi Akiva says that “love your neighbor” is the fundamental principle of the Torah. Another sage, Hillel the Elder[1], defines this commandment somewhat differently: “Whatever is hateful to you, do not do to another—this is the essence of the entire Torah; the rest is only commentary.”
If a person treats his neighbor well, he will never harm him or damage his property and will never listen to (or spread) gossip about him.
And many of the Torah’s laws deal precisely with matters of property or relationships between people.
3. This commandment addresses not only our feelings, but also our thoughts and actions.
To love your neighbor means wishing him well just as you wish yourself well, showing him the same compassion, and treating him with respect.
Whatever a person would want others to do for him, he must do for others. Likewise, whatever is hateful to him, he must not do to other people.
The principle behind this commandment is that others will treat a person in the same way he treats them—and, ultimately, this will lead to peace and mutual understanding.
The Torah does not present this commandment as a requirement only for highly spiritual people, which means that anyone can fulfill it by adopting the appropriate attitudes.
**** Once, Rav Shalom Sharabi saw a barefoot blind woman on the road, being led by the hand by a little girl. It was raining heavily, and the woman was struggling to walk through the mud. The girl had no warm clothing and was shivering with cold. The rabbi approached them, took off his shoes, and put them on the woman’s feet. Then he took off his large scarf, wrapped it around the girl, and went on his way. **** Rabbi Zundel of Salant (the teacher of the renowned Rabbi Yisrael Salanter) got up every night to draw water from a well for a lonely elderly man who lived nearby. He did this for many years, even when he himself was advanced in age. For a long time, no one knew about it, until the old man himself noticed him.
[1] Rabbi Akiva and Hillel the Elder were sages of the era of the Tannaim, the compilers of the Mishnah. Hillel lived while the Second Temple was still standing.