Rabbi Akiva taught that the love of one's fellow Jew (Ahavat Yisra'el, in Hebrew), commanded in the Torah in the well known verse, "You shall love your neighbor as yourself" (Leviticus 19:18), is the "great, all inclusive, principle of the Torah." When approached by the convert with the request "teach me the whole Torah while I stand on one foot," the sage Hillel the Elder replied: "What you hate done to you do not do unto others. This is the entire Torah on one foot; the rest is commentary, go and learn."
The Ba'al Shem Tov taught that true ahavat Yisrael is to love, from the depth of one's heart, a Jew "who one has never seen." This implies that one's love of Israel is based upon the superrational identity of souls, irrespective of any conscious ground for friendship.
Rabbi Shneur Zalman of Liadi said that the love of Israel is in fact the consummation of the love of God, for when loving Israel "one loves what one's Beloved loves [for God loves Israel, as is said `I love you, says God`]." In love of Israel one should be conscious that every Jew possess a unique holy quality unparalleled by any other Jew (this in addition to the essentially superrational root of love that we are all one and sibling "children of God"–"no matter what").
Ahavat Yisrael is first an experience of our all being "cells" or "limbs" of one spiritual body, whose blood and life force flows through us and connects us all, and then to experience an absolutely common "self" which encompasses us all. At the first level of experience one may still sense evil emanating from the other, whereas at the second level "all sins are covered (become invisible) by love."
"Love of the Jewish People" (אהבת ישראל) = 949 = 13 ∙ 73, or the value of "love" (אהבה) times "wisdom" (חכמה). The inner spiritual property of wisdom is selflessness, the prerequisite for true love. Furthermore, as all Jewish souls are essentially "wise," one's love for one's fellow Jew is the greatest expression of one's innate wisdom. (The sefirah of wisdom is the highest on the right axis of the sefirot; loving-kindness, whose inner experience is love is situated immediately below wisdom and thus love recieves light and inspiration from wisdom and its inner experience of selflessness).