http://revach.net/article.php?id=3427

Section:  Avodah   Category: Ahavas Yisroel
Rav Noach Weinberg Zt"l & Ybcl"c Rav Elyashiv Shlit'a - Returning Lost Sheep
"Ki Sifga Shor Oiyivcha Oy Chamoiroi Toi'eh BaDerech Hasheiv Tishivenu Loi", when you chance upon the lost sheep of you nemesis or his donkey, return it to him (Mishpatim 23:4). Hashavas Aveida means more than lost sheep and other material possessions, says Rav Elyashiv.  It also refers to another kind of Aveida, that of lost souls.  Just like there is mitzva to announce a lost item and restore it to its owner, so too every single person is obligated to help a lost soul "M'Bnei Tzion Yayekarim" from the precious Jewish children, find their way back into the fold.

Not only someone who has wandered away, but also someone who has been rejected by society.  Like the pasuk says in Ki Seitzei (22:1), "Lo Sireh Es Shor Achicha... NidachimV'His'halamta Meihem", do not see your brothers ox... cast out and you will ignore them.  Everyone, regardless of where he is or how he got to where he got, must be returned to his father in Shamayim.

The gemara says (Makos 24a) that Rav said, "I am scared of the pasuk [in the tochacha Bechukosai 26:38] "Va'avaditem BaGoyim", you will be lost among the nations."  Rav Papa consoled him and said, "maybe it means like a lost item that is looking to be found, like it says on the pasuk (Tehilim 119:176) Ta'isiK'Seh Oveid Bakesh Avadecha", I have gone astray like a lost sheep, seek your servant."  Rav Elyashiv explains that finding your inanimate object is difficult because it just sits there and doesn't help you find it.  A sheep that is separated from the herd, on the other hand, is much easier to find as she sits crying in her solitude, and so badly wants to return to the herd.  She is begging to be sought..

Deep within our lost brothers and sisters their souls cry to be found.  This makes them the easiest objects to find.  Like Rav Noach Weinberg zt"l would say, each one of us has an obligation to go out there and help them.  We can all do it, we only have to really want to.  He claims we can all do a better job than him, and boy what a job he did!  Everything we manage to do is with the help of Hashem.  Do you not think Hashem will help you return his precious children to him?