“Haven’t you read,” he replied, “that at the beginning the Creator ‘made them male and female,’[a] 5 and said, ‘For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh’[b]? 6 So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.”Matthew 19:4-6
Did God really say that marriage is exclusively for a man and a woman? Some will point to instances in the Bible where one man had more than one wife. Yes, you read of Abraham and Sarah and the child Abraham fathered with Hagar. The kings of Israel had many wives and concubines. It’s true, but in each instance, the Bible provides a description not a prescription for behavior.
When you consider the instances of sex outside of marriage or polygamy such as Jacob and Leah and Rachel, can you think of any of those relationships that were ideal in any way? The result was often a family of dysfunction and chaos.
God’s prescription regarding marriage is clear and in the verses above Jesus answers His critics succinctly.