When a Jew extends a friendly hand to help a stranger find his way back to his heritage, he does it humbly. Why?
The instinctive love that he feels for his fellow reminds him that every single Jew is a precious child of G-d, a unique individual of infinite worth. That same instinctive love reminds him that we are all responsible for one another, for we are all brothers, our souls linked together in a common destiny. This approach is crucial to the philosophy of Chabad-Lubavitch, and underlies all the outreach efforts that it inspires.
Yet outreach is only one visible aspect of ahavas Yisrael, the obligation to love a fellow Jew. On a broader, day-to-day level, To Love a Fellow Jew shows how chassidic thought illuminates this seemingly simple obligation. The chassidic teachings in this work enable imperfect individuals to develop the ability to love other imperfect individuals – not only to relate with compassion and sensitivity to relatives and strangers who may be reacting stressfully to stressful situations, but in fact to love unlovable people.
And if this has been a necessary skill in all generations, how much more desperately is it needed in the present era of confusion, just before the coming of Mashiach. The Holy Temple was destroyed because of undeserved hatred, and it will speedily be rebuilt through undeserved love.