Combining two lives into one takes a lot of work that many people are not properly prepared to do. There are not a lot of healthy relationships featured in our surroundings or present in homes for couples to learn from or ask for guidance when struggling. There are few schools or youth organizations teaching how to have a functional relationship.
So couples go at it alone, trying their best to create their own rules and techniques, but without a model, sometimes this goes astray and couples need help getting back on track. Sometimes personal histories create deficits in certain skills, knowledge, or experience that can lead to underlying issues in relationships.
Therapy focuses on becoming aware of these underlying individual and couple issues as well as developing communication skills and nurturing techniques to reduce frequency and intensity of conflicts and break the cycle of recurring arguments. Therapy can also be utilized to enhance a relationship by increasing intimacy.