Why could people survive in those days only by uniting? What did the ancient Slavs do? Why did the ancient Slavs deify nature?

Why could people survive in those days only by uniting? What did the ancient Slavs do? Why did the ancient Slavs deify nature? From whom did the Slavs defend themselves, enclosing their settlements with a high palisade?

Life used to be much more complicated and dangerous than it is now. And in order to survive, the Slavs had to unite. Firstly, to maintain the economy; it is more convenient to lead a life when there are more people, right? Someone can clean up, someone can hunt, someone can dominate, and so on. Secondly, to protect against the raids of the nomads – by uniting, it was easier to repel their attacks.
The ancient Slavs also deified nature. They could not explain what was happening around, so they thought they were gods. For example, if thunder roars, God is angry with them for something.
The Slavs also defended themselves with a palisade both from the same nomads and from other tribes and wild animals.