I would have to say I do beleave in them. I know I beleave me and my fianc'e are. I still remember when we met. All I did was hear her voice, did not even see her and I knew she was the one. It was weird because before then I did not beleave. Now does having a soul mate make things easer? Nope not at all. Just because two people are meant to be together does not mean they will be. Any relationship takes work. Some how you have to show your love but not smother. You have to trust but be involved. You have to love but let go. You have to hold them but keep your distance. Love is full of emotions, up's and down's, rivers to forge and streams you can step across. Love is an adventure that is worth every step. The question about love is are you ready to put one foot in front of the other and keep makeing those steps no matter what. As I write this I relize alot about myself. Me and my fianc'e have been having some problems, nothing major but you can feel it in the air. I relize now that for some reason I stopped walking beside her. Going to fix that today.
I do believe, but like Immortalone said, it doesn't make anything easier. A happy, long-term relationship takes effort from both parties. What does it matter to have a magical connection if energy is not put into cultivating it and making it stronger? I believe that I have found my soulmate (wife of 8 years), but I may very well lose her soon because I did not fully understand what it took to have a truly successful marriage. She does not yet understand these concepts yet, but I hope she will soon before she gives up on a once beautiful thing.
I think that the whole idea of a "soulmate" is dangerous in the sense that it is "black or white thinking," implying that there is only one person out there for you - when in fact, there are probably many people who one could be happy in a relationship with.
It can also be dangerous in the sense that if someone feels that a partner is their "soulmate," but that partner is abusive and unwilling to change - latching on to the "soulmate" idea makes it mentally harder to leave that person. There are plenty of people in unhealthy relationships with others they consider "soulmates."
While this may not be the way everyone looks at the concept of a "soulmate," it's what comes to mind when I think of the idea. To me, it also implies categorizing someone into this "ideal partner for them" which no one can realistically achieve.
I do believe in soulmates, but I don't believe that your "soulmate" has to be the person you are in love with. I consider my soulmate my best friend. We live in different states now, and we don't talk all the time...but if one of us needed the other, we'd be there no matter what. Sometimes, what we don't say to each other is just as important and telling as what we do say to each other. I think a soulmate is someone who understands you and accepts you without question or judgement and just loves you for you.