Simple answer - "Because God!"
In Genesis 1:27-28 God's involvement in the process is made clear:
- So God created mankind in his own image,in the image of God he created them; male and female he created them. God blessed them and said to them, “Be fruitful and increase in number; ...
And even clearer in Genesis 2. Thomas quoted the core of this, but the extra detail adds usefully to understanding the process:
Genesis 2: 18-24 (excerpts)
- The Lord God said, “It is not good for the man to be alone. ... But for Adam no suitable helper was found. ... Then the Lord God made a woman ... and he brought her to the man. The man said, “This is now bone of my bones and flesh of my flesh; she shall be called ‘woman,’ ... That is why a man leaves his father and mother and is united to his wife, and they become one flesh."
Korosia said:
These verses make it clear that God created man and woman, but I'm not seeing where it explains the connection between that event and a literal marriage between Adam and Eve.
You thought Thomas's answer explained it - but an expanded
context example makes it less clear somehow? Yes? || In the NIV
Genesis refers to Adam's wife 6 times. As Luke noted, the same word
could be translated "woman" but it is still obvious that the context
implies wife. For this to have happened then God's active involvement
obviously made the difference.
It seems highly clear that when:
The Lord God said, “It is not good for the man to be alone. ... But for Adam no suitable helper was found. ... Then the Lord God made a woman ... and he brought her to the man.
as the other animals all had mates, that God is not 'just' meaning the woman is to be a 'helper'. You could try that interpretation, but I doubt that many would find it convincing. And,
The man said, “This is now bone of my bones and flesh of my flesh; she shall be called ‘woman,’ ...
This he says standing before God. Again, you could see that as Adam 'repurposing his helper into 'one flesh', without God intending it. I doubt that you could sell the idea :-)
That is why a man leaves his father and mother and is united to his wife, and they become one flesh."