Late to this party, but decided I would weigh in anyway.
Do I believe in soul mates? I used to. it was a very hard belief to let go of. Not because of how much evidence surrounds it, but because of how hard I wanted to believe it.
Think about it. If you have a soul mate, then that basically means that whatever you do, wherever you end up, this one person in the universe will find you (and you him/her) and that will be it.
What is the point of life then? If it's all laid out for you like that?
This was hard. I struggled for a long time with the notion of free will vs. God being all-knowing. How could they co-exist? Don't all things happen for a reason??? That's where I would get stuck:
If that is true, then do people get cancer for a reason? Do people get cheated on for a reason? Lose their loved ones for a reason?
No. No, they don't. What I do believe is that God (or whatever you believe in) gives you the opportunity to make the best out of any scenario. It doesn't happen for a reason, but you can bring reason to it by what you do with it.
Bringing this full circle, this is what helped me to understand soul-mates. Soul mates (plural) in my opinion are people in your life that you have a deep connection with, that help you with tremendous amounts of growth that maybe wouldn't have been possible otherwise. They understand you, love you for who you are, encourage you, etc. I have one for sure in my life...She's a woman, as am I, and we are both heterosexual. at the same time, I have no doubt that her existence/involvement in my life has brought about the most personal healing, growth, self-love, knowledge, understanding, etc. than I have EVER experienced. I also know that due to the nature of our relationship, she very well may not be in my life for long/ever. Maybe only 5 or so years.
She reminds me a lot of, well, me. Just a little older. And how amazing to see myself in someone that I love and admire so much?!?!
If you are looking for one man (or woman) to come into your life and be that person, it's not impossible...nor is it impossible to have more than one. Just know, that it may not be a lover, sexual partner or life partner.
I no longer believe that the one person we marry will necessarily be our soul mate. I believe that he/she could be, but don't have to be in order for us to build an awesome, loving, deep relationship with them.
I don't think that a soulmate is someone we should aspire to meet, I think we should aspire to connect with all whom we meet.