In order to have a happy companionship or a harmonious and lasting marriage, many people feel they need to find their soul mate.
A soul mate may imply finding by chance or some other means someone who is perfectly suited to another in temperament or who strongly resembles another in attitudes or ways of thinking. As a student of Christian Science, I have learned that a lasting and harmonious marriage is a demonstration of our spiritual completeness.
The story of Ruth, in the Bible, and the chapter “Marriage” in Science and Health with Key to the Scriptures by Mary Baker Eddy provide good examples and definitions of what spiritual completeness is.