4 And He answered and said to them, “Have you not read that He who made them at the beginning ‘made them male and female,’ 5 and said, ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’? 6 So then, they are no longer two but one flesh. Therefore what God has joined together, let not man separate.” (Matthew 19:4–6, NKJV)
Jesus laid out three distinct reasons that it is not lawful “for a man to divorce his wife for just any reason” when the Pharisees asked Him whether it was so (Matt. 19:3). (1) The Genesis of Marriage (v. 4). God, not human beings, created marriage. His purpose for marriage, which is between “male and female,” is the final word on the matter. (2) The Condition of Marriage (v. 5-6). Marriage is a “one flesh” relationship. When married, the man and woman are no longer independent; they are joined by God as “one flesh.” As surely as we do not naturally separate flesh from flesh, so neither is it natural to separate husband and wife by divorce. (3) The Prohibition of God (v. 6). God declares we are not to separate (put an expanse between) what He joins together, namely, the husband and wife. We must solidify in our hearts this unchanging edict from God: Marriage is given by God, and is between one man and one woman, for life. (Jesus will give one exception to this rule in verse 9, and that is exactly what it is, an exception to the rule.) It is transgression against God to sunder what He has joined together.