The Magic Barrel, like the other stories written by Bernard Mallamud, a Jewish writer, is concerned with Jewish theme and Jewish life. Although the Jewish communities mostly live meager lives, their lives are controlled by a lot of religious rules and laws which help them keep far away the Devil or more important closer to their Great Father, God. Here, the story reminds us, or at least the Jews, one of their most important principle, a principle above all principles: "Love your God with all your heart, with all your mind, with all your soul. Love people as yourself". Though the principle is obviously hard to completely follow, it is so important and basic, especially to ones who are the community leaders like Leo Finkle in the story.
In spite of the visible requirements such as an educational degree and a wife that he would get sooner or later, the drama of Leo Finkle, a will-be rabbi, was that he had no love for both God and fellow men.
Thanks to Lily's probing question, Leo found out " he truly was unloved and loveless". That explained why he always found something wrong with all the girls Mr. Salzman had introduced. If he could not love or sympathize with his fellow men who were real and visible, how he could love God, a supernatural and invisible one. It meaned that what he had now was nothing of the spirit of the law but of formalism. Therefore he, a rabbi who was responsible for teaching the community the law by which they could get closer to God, was rather closer to the Devil. It not only made him panic, but also was a drama for the Jewish community.
The magic barrel here has made a magic that helped Leo find...