""Love your neighbor as yourself" - Leviticus 19:18.
Perhaps nothing is more harmful to the Jewish people than the modern idea that Judaism is a religion. We are not a religion; we are a single soul illuminating many bodies, making them a single unity.
A healthy body is one where its different parts work in harmony. A healthy Jewish community is a large family where each individual loves the other as themselves. When one is going through difficult times, the others help. When one finds good fortune, the others celebrate.
Love for those closest to you nurtures love for the extended family of humanity and, from there, love for all of God's creatures. But if love doesn't begin at home, where will it come from?
In practice...
1. Begin each morning by saying, "I accept upon myself the precept to love my neighbor as myself.".
2. Follow Hillel's rule: "Do not do to others what you would not want done to you.""
3. Speak only good things about your neighbors. Don't listen to anything bad unless a real benefit will come from the conversation.
4. Take care of your neighbor's possessions and property as if they were your own.
5. He is always on the lookout for an opportunity to do someone else a favor.