Every Jew Holds a Share
Rav Chaim taught that because Israel are partners in Torah and mitzvos, even someone with no merit of his own shares in his friend's.
Rav Chaim explains the saying that every member of Israel has a portion in the next world. Since Jews are responsible for one another, he writes, they are partners in observing the mitzvos and in sustaining and learning Torah, and as business partners divide earnings, so Yisroel divide the fruit of each other's learning and good deeds. His proof is the verse that calls the entire people righteous. Every Jew has his own merit. And if you happen to meet a person who looks completely empty, the verse continues that they will inherit the land forever. "Forever" includes even the one who has nothing of his own, because he too is a partner in the merit of the whole nation.
Source: Pe'ulas Tzaddik LeChaim (Siach Israel, Jerusalem 1998), opening pages on love of Israel
Today, when you meet someone whose observance or learning seems thin, resist the quick thought that he has nothing. Instead remind yourself that you and he are partners in one Torah, and that his merit is also yours. Then do one concrete thing for that partnership, such as greeting him warmly, inviting him to a shiur or a Shabbos meal, or speaking well of him to someone else. Treat his portion as something you share in.