One of the comprehensive mitzvot of the Torah is the mitzvah of ahavat yisrael, the love for a fellow Jew, which the sages of the Talmud declared to be "a great principle of Torah," and the "basis of the entire Torah."
Essentially, the mitzvah points to the unity of all Jews, as if they constitute a single entity. As such, any action by a Jew, whether negative or positive, is consequential to the entire Jewish people. Certainly the fulfillment of mitzvot by any individual Jew affords the Jewish people tremendous strength.
Every Jew, wherever he or she may find themselves, even a solitary Jew in the most remote corner of the earth, must remember that they are part of the whole Jewish people and representatives of the entire Jewish people--the one people ever since the Torah was given at Mt. Sinai, until the end of time.
The division of Judaism into "Orthodox," "Conservative," "Reform," etc., is artificial. For all Jews have one and the same Torah, given by the one and same G-d, though there are more observant Jews and less observant Jews. To tag on a label does not change the reality of Jewish essence.
The three loves--love of G-d, love of Torah and love of one's fellow--are one. One cannot differentiate between them, for they are of a single essence. And since they are of a single essence, each one embodies all three.
So if you see a person who has a love of G-d but lacks a love of Torah and a love of his fellow, you must tell him that his love of G-d is incomplete. And if you see a person who has only a love for his fellow, you must strive to bring him to a love of Torah and a love of G-d--that his love toward his fellows should not only be expressed in providing bread for the hungry and water for the thirsty, but also to bring them close to Torah and to G-d.
