The soul mate ideal both raises barriers of entry to those seeking to enter relationships, and harms existing relationships.
First, our obsession with finding our soul mate twists how we seek a mate. It tempts us to set unbelievably high standards for a mate—the perfect complement in every possible way. But some areas of compatibility are more important than others: for instance, shared religious faith is more important to sustaining a marriage than shared affinity for gourmet chocolate. (Not that there’s anything wrong with being a foodie!)
Rejecting the idea of a ready-made soul mate doesn’t mean one should have low standards or no standards for finding a mate. Rather, you need criteria that aren’t impossible to meet but can screen people out in a meaningful way. It’s still possible to find many people who share your common interests, goals, and ambitions—even in small towns. That’s your pool. Don’t artificially narrow it.