As the original post said, the way to get these people back is by showing them that Judaism is a great thing, and make them want to be frum. I was once a teen at risk, also. I didn’t keep Shabbos, wasn’t careful about kosher, etc. There were many things that all caused it, which I won’t write about now (unless people want to hear it). Basically, I didn’t see the beauty of being a frum Jew, I thought it was restricting, and that the rabbis who were supposed to guide people were hypocrites, and just not good people.
I had many friends who distanced themselves from me. Others remained close, but made certain things clear – they didn’t want to discuss movies, or which girl I was currently dating, or things like that. If we stayed away from those things, they were fine with spending time with me.
Luckily for me, I found a few Rabbis I really respected, and came to see the true beauty of being a frum Jew. I still think that most of my family doesn’t really get it, even though they’re probably much more yeshivish than I am, and know much more about many things than I do – my brothers are either learning in Lakewood or used to and are in a different kollel now, some of my brothers learned in Brisk in Israel, etc. However, I feel I see things differently then they do. I won’t say they’re more frum than me, because who am I to judge what makes a person frum?
Anyway, the point is, many people won’t associate with an at-risk teen because there’s nothing to relate to. Would you be friends with someone who wasn’t a frum Jew, who made you uncomfortable? Teens at risk make many people uncomfortable. I had friends who would do drugs. Would you feel comfortable hanging out with someone like that? Some people can handle it, some can’t. It’s where you can find out who your real friends are – real friends will stick by you no matter what. I had friends who didn’t judge me when I wasn’t frum, they slowly encouraged me to become frum again. I know that they will stick by me when I need them, and they always have.
In closing, just remember – punishing your at-risk child will not help, it will only make them more determined to stay away. You have to make them want to be frum because being frum is a beautiful thing, not because they’re scared of punishment.