Great Rule of Torah

... you must love your neighbor as (you love) yourself. I am God.                                            Leviticus 19:18

Rabbi Akiva says: this is a great rule of Torah.

                                                      Midrash Safra 2:4 

Pitron Torah (a 10^th century Midrashic compilation) [Kedoshim 80] states that our verse is one of two verses upon which all Torah depends, the other being “Love God your Lord with all your heart, with all your soul, and with all your might.” [Deuteronomy 6:5] My father wrote: “love your neighbor as you love yourself” is as important as “love your God.” One cannot be a religiously observant Jew without fulfilling both aspects of Judaism: between man and God and between man and fellow man.

In truth, love of God and love of one’s fellow are interrelated. Rabbi Eliezer of Mainz [1090-1170] writes that in order to truly love God, one must love those whom He loves, and as God declared through His final prophet [Malachi 1:2] “I love you,” so too we must love our fellow man.

Ḥassidic Master Rabbi Menaḥem Naḥum of Chernobyl [1729-97] comments that love of God can be fully achieved only by including oneself within Klal Yisrael, and therefore, fulfillment of the mitzva of loving one’s fellow is a necessary component of loving God.

Some suggest a reciprocal relationship: through loving one’s fellow, one will come to a greater love of God (through the realization that it is He Who created us all) and as well, love of God will increase one’s love of his fellow man.

Ultimately, love of one’s fellow, as is true of all mitzvot bein adam l’ḥavero, is also a mitzva bein adam laMakom. All of the above insights derive from the final words of the verse: “I am God.” Thus, the basis of loving one’s fellow is not the social compact which is necessary for society’s survival, nor rational reasoning, but rather because “I am God.”