What do you think of the idea of "soul mates" as a Catholic? I believe that they exist but not everyone has one.
Good question! We're told in the Bible that man and woman are made for each other, and there are plenty of touching love stories in the Old Testament, but nowhere is the idea of "soul mates" generalized to everyone.
Actually, what marriage counselors tend to speak of is pretty much the exact opposite. Rather than immediate "love at first sight," being meant for each other from all eternity, a loving relationship tends to grow naturally over time. The more time two people spend with each other, and the more affection they show for each other, the deeper the bonds of love become, and harder to break too.
So you can feel an inexplicable attraction to lots of people, but you'll only fall deeper in love with the person you constantly show love for. And then that, in a certain sense, is your "soul mate," but it happens after the fact (thanks to your "investment" in that person) rather than before the fact (thanks to "destiny").
So if you'll accept that redefinition of it, I'll agree with you that they exist (plenty of wonderful people I know are very happily married) and that not everyone has one (I don't!).
That said, does God "have someone for you"? The safest thing to say is that he made you to love and to be loved, and that he's set you in the middle of a whole lot of wonderful people who could possibly be yours. In his Providence, he can certainly guide you to someone by special intervention, but in general he's already set you on the path to a life of love!
In other words, if you have the vocation to marriage, you don't necessarily have the vocation to marry Joe Smith or Mary Brown... but God won't leave you high and dry. Stay close to Him!
God bless you.
- Father Shane