18 The LORD God said, “It is not good for the man to be alone. I will make a helper suitable for him.”
19 Now the LORD God had formed out of the ground all the beasts of the field and all the birds of the air. He brought them to the man to see what he would name them; and whatever the man called each living creature, that was its name. 20 So the man gave names to all the livestock, the birds of the air and all the beasts of the field.
But for Adam no suitable helper was found. 21 So the LORD God caused the man to fall into a deep sleep; and while he was sleeping, he took one of the man’s ribs and closed up the place with flesh. 22 Then the LORD God made a woman from the rib he had taken out of the man, and he brought her to the man.
23 The man said,
“This is now bone of my bones
and flesh of my flesh;
she shall be called ‘woman,’
for she was taken out of man.”
24 For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh.
As God looks down on Adam, He notes that it is not good for him to be alone. Then species after species of animal paraded past Adam and he named them. As Adam saw all of the animals it dawned upon him that he was the only one of his kind. All other creatures had a mate but there was none that was suitable for Adam.
One of the reasons God gave Eve to Adam – and thereby beginning marriage – was as a helper and companion. God did not want man to live his life alone and so He created someone who was compatible for Adam.
Solomon writes about the benefits of having another person as a companion in Ecclesiastes 4:9-12.
9 Two are better than one,
because they have a good return for their work:
10 If one falls down,
his friend can help him up.
But pity the man who falls
and has no one to help him up!
11 Also, if two lie down together, they will keep warm.
But how can one keep warm alone?
12 Though one may be overpowered,
two can defend themselves.
A cord of three strands is not quickly broken.
Another purpose of marriage is procreation. Obviously marriage is not required in order to have children. However it is God’s will that two people be married before having children. For more on this, see the article “Why Should I Wait Until Marriage for Sex?”
We are told to be fruitful and multiply. This applies in a physical sense but also in a spiritual sense. Parents pass on their wisdom, morals, and faith to their children. This is done most effectively within a close knit family.