What is God's definition of marriage? According to Scripture, it's a one-flesh, whole-life union between one man and one woman. This union covers every aspect of human existence: the physical, the sexual, the mental, the emotional, the moral, the spiritual, and the economic. This definition is summed up in the words of Genesis 2:24: "Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh."