We know Solomon's heart because he communicated it in prayer. The great thing about prayer is that you say things to the Lord that you would never say to each other in casual conversation. For example, when a woman hears her husband praying earnestly about his situation at work, she may realize, Wow, I had no idea this was such a difficult issue for him . Likewise, when you describe your commitment in prayer to obey and follow Christ, you are communicating to your spouse that he or she can trust that you will be committed to fulfilling all your responsibilities in your marriage too. What a sweet fruit of trust and intimacy this will bear.
Prayer establishes deeper companionship.
Think with me for a moment. If you will notice, these problems are naturally addressed by my first three points. As you humbly pray with one another, communicating your needs before God, you will automatically grow in a spiritual unity with one another which results in a deeper companionship. And remember, companionship is the most important reason that you are married. If you lack companionship in your marriage, prayer is one very important way to deepen it.