1. God Created It.

Genesis 2:18-25 (ESV)
18 Then the Lord God said, “It is not good that the man should be alone; I will make him a helper fit for him.” 19 Now out of the ground the Lord God had formed every beast of the field and every bird of the heavens and brought them to the man to see what he would call them. And whatever the man called every living creature, that was its name.

20 The man gave names to all livestock and to the birds of the heavens and to every beast of the field. But for Adam there was not found a helper fit for him. 21 So the Lord God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh. 22 And the rib that the Lord God had taken from the man he made into a woman and brought her to the man.

23 Then the man said,
“This at last is bone of my bones
and flesh of my flesh;
she shall be called Woman,
because she was taken out of Man.”

24 Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. 25 And the man and his wife were both naked and were not ashamed.

2. Sin marred it.

Genesis 3:1-7;21 (ESV)
3:1 Now the serpent was more crafty than any other beast of the field that the Lord God had made.
He said to the woman, “Did God actually say, ‘You shall not eat of any tree in the garden’?” 2 And the woman said to the serpent, “We may eat of the fruit of the trees in the garden, 3 but God said, ‘You shall not eat of the fruit of the tree that is in the midst of the garden, neither shall you touch it, lest you die.’” 4 But the serpent said to the woman, “You will not surely die. 5 For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.” 6 So when the woman saw that the tree was good for food, and that it was a delight to the eyes, and that the tree was to be desired to make one wise, she took of its fruit and ate, and she also gave some to her husband who was with her, and he ate. 7 Then the eyes of both were opened, and they knew that they were naked. And they sewed fig leaves together and made themselves loincloths.

21 And the Lord God made for Adam and for his wife garments of skins and clothed them.

3. Christ and the church perfectly model it. (Ephesians 5)

Ephesians 5:17-21 (ESV)
17 Therefore do not be foolish, but understand what the will of the Lord is. 18 And do not get drunk with wine, for that is debauchery, but be filled with the Spirit….21 submitting to one another out of reverence for Christ.

22 Wives, submit to your own husbands, as to the Lord. 23 For the husband is the head of the wife even as Christ is the head of the church, his body, and is himself its Savior. 24 Now as the church submits to Christ, so also wives should submit in everything to their husbands.

Ephesians 5:25-33 (ESV)
25 Husbands, love your wives, as Christ loved the church and gave himself up for her, 26 that he might sanctify her, having cleansed her by the washing of water with the word, 27 so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish. 28 In the same way husbands should love their wives as their own bodies. He who loves his wife loves himself. 29 For no one ever hated his own flesh, but nourishes and cherishes it, just as Christ does the church, 30 because we are members of his body. 31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” 32 This mystery is profound, and I am saying that it refers to Christ and the church. 33 However, let each one of you love his wife as himself, and let the wife see that she respects her husband.

4. Believers should cherish and encourage it.