This question seems to be asked quite often. Below is my standard answer.
No! I don't believe in having (a) soul mate as in only one person could fulfill my desires. In a world with 7 Billion people odds are there are a lot more than one person who would "get you", share your same values, want the same things for a relationship/marriage, and agree with you on how to obtain those things.
We decrease or increase our odds of finding love by the way we (include) or (exclude) others. If I say "the one" must be of my own race I could be eliminating 6 billion people sight unseen! If I say "the one" must share my same faith, currently live in my country, state, or town I could go from 7 billion options to 20,000 and this is all (before) we get to such things as height, weight, hobbies/interests. occupation, sexual compatibility, and personality!
Last but not least we say "the one" must be liked or loved by our family/friends and vice versa. When a person gets through (excluding) people is it any wonder why they find it so difficult to find someone? Awhile back I wrote a hub on this subject. http://dashingscorpio.hubpages.com/hub/thereismore