Two people are better than one. They get more done by working together.
If one person falls, the other can help him up.
But it is bad for the person who is alone when he falls. No one is there to help him.
If two lie down together, they will be warm. But a person alone will not be warm.
An enemy might defeat one person, but two people together can defend themselves.
A rope that has three parts wrapped together is hard to break.