The Purpose of Marriage: Gen 1 or Gen 2?
The bible begins with two creation stories, and each has its own purpose. Gen 1 tells the story of how all creation came to be, with the creation of humanity, male and female, as the culmination of creation. In this story, which is dominated by themes of generation and fertility, God tells people to be fertile and multiply, fill the earth; eat these things for your food, and leave those things as food for the animals. This is a story about the world, and humanity’s relationship to the world.
Genesis 2 tells a story about humanity. In Gen 2:18, God says “It is not good for the human to be alone,” determines that none of the animals are suitable companions for the human, and fashions a suitable companion from the side of the human, from the very same flesh. (Note the single-nature anthropology implied here: ie, there is a single human nature shared by women and men.) Gen 2:24 says “that is why a man leaves his father and mother and clings to his wife, and the two of them become one body.” This is a story about the origin of marriage.
Notice that the story about the origin of marriage says nothing about procreation.