Each of us is a soul. We have been told that we "have" a soul, but that's not the same thing. To have a soul would indicate that we are primarily an ego or a personality that in some way "possesses" a soul. Our essence IS the soul and all aspects of ego and personality flow from that essence. At its core the soul is pure, but habits, tendencies, and imbalances often obscure some of that inner light. Our spiritual work is to correct whatever shortcomings may be preventing the light of our sould from shining through.
If I set my heart upon another person, then I cannot live without that person. My heart becomes divided. If I give my heart to my life, on the other hand, if I give my heart to the journey with God, then my heart can be whole in a relationship with another. I can be heart and soul in the relationship because I am heart and soul in the journey of my life.