For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh. - Genesis 2:24, NIV
Some people may consider the intimate side of marriage as somehow being “unspiritual.” But if you stop to think about it, the first person who ever had a sexual thought was God. In a perfect world, at the beginning, love expressed in marriage in a mutually respectful sexual relationship was God’s idea. It was designed as pure, holy, and pleasing to Him.
Dr. Ed Wheat, a prominent marriage counselor, has pointed out that if the physical side of marriage deteriorates, every other aspect of marriage will soon be affected (Love Life for Every Married Couple). When God commanded Adam and Eve to “be fruitful and increase in number” (Gen. 1:28, NIV), He seemed to be saying, “Make sex a priority in your marriage,” not only for the procreation of the race but also in order to maintain the healthy, intimate, physical unity with each other for which we were created.
From God's Story