Recently, the web comic XKCD addressed the question, "What if everyone had only one soul mate, a random person somewhere in the world?" XKCD's response  was not optimistic -- in particular, a graph of "found soul mate" versus "alone forever" is disturbing. Do you have a different take? Is there any way around the pessimistic conclusion that it is unlikely that most people will actually find their soul mates?
Beshert? Be honest.
If you are partnered for life with someone who makes you really happy, then for all intents and purposes, that person is your soul mate. There's no need for a mathematical equation or chart or graph to convince you that this really is the "one" for you. If it's actually a satisfying relationship, you're not going to leave your partner to travel the world to see if you lock eyes with someone else who's a more perfect fit.
If you are currently partnered, you also may have had that "aha" moment when things just clicked. But perhaps you had an ex before this current partner, maybe someone you thought you'd be with forever, but circumstances just weren't quite right. Your conclusion can either be that the first person wasn't your beshert (soul mate), or that, given a different alignment of other factors, you could have been happy with more than one person.
Now, if you are not currently in love, at least not with someone who loves you back, XKCD's take on the soul mate situation may be more discouraging. "What if I'll never ever meet my soul mate because s/he lives in a remote jungle on the other side of the planet?" This theory just doesn't resonate with me, in part because I can't imagine spending my life with someone with whom I have no cultural commonalities.
Once you start narrowing down to people with whom you share some frame of reference, the possibilities become much more reasonable. You might be thinking, "But I spend so much time with other single Jews who live in the same city and I still haven't found anyone I like a little bit, let alone love a lot." That just means you haven't met the right person yet, not that the right person lives in a cave in the desert.
I didn't say "soul mate," though, I said, "the right person," because love can depend on timing and circumstances — both of you being in the same place and ready for a deeper relationship, and so forth. I like the idea of writing the narrative in reverse. Once you meet someone and fall in love, come up with all the reasons why you're meant to be together, all the scenarios in which you should have met previously but didn't, all the things you have in common that prove how right you are for each other.
You and this person don't have to be predestined since the universe began in order to be really and truly right for each other right now. Once you meet, you then become soul mates. I think that approach works just as well if not better, and it takes off some of the pressure to find the one. You can be just as happy, if not more so, with one.
Whether you want to hold onto XKCD's theory, mine, a combination of both or something else entirely, I'm convinced that you won't meet the right partner until you put yourself in places where you can meet someone. Don't sit home expecting your soul mate to knock on your door and sweep you off your feet. Be available, be open and ready, and one of these days, your soul may be just as surprised as you are to meet someone really great.