When a couple comes to therapy it's generally because their communication has deteriorated over time, with the stressors of raising children, perhaps financial concerns and in-laws, work and commuting, adding to the already difficult task of keeping love and romance alive in a marriage. You may be interested to browse some of my ideas on relationship and my commitment to supporting planning the marriage rather than the wedding - premarital counselling.
Marriage and family therapists are trained to help you get to the root of the problem by asking searching and insightful questions, taking an objective, curious stance about what's been happening in your relationship since you met and especially since the deterioration began. They are trained to see patterns of behavior, threads of similarities that you may not be able to see, and which give you insight into why you do what you do - then we move on to learning new skills to move forward in a different way.
Relying on the tried and tested theories of Dr. Harville Hendrix and Dr. John Gottman, I listen for the communication skills you already have and offer you additional ones to add to your repetoire. Homework is standard procedure - meeting with a clinician for an hour a week and expecting your relationship to turn around is truly magical thinking - you need to be in different practices with one another on a daily basis in order to produce a new outcome.
I encourage you to use Dr. John Gottman's The Seven Principles for Making Marriage Work, Gary Chapman's The Five Languages of Love and on occasion may recommend Dr. Harville Hendrix's Getting the Love you Want.