What effect does Achebe achieve with his repetition of the phrase "they came" in the second paragraph?

This tells us the power and respect that the Oracle had. All kinds of people came for many different things. The Oracle drew a big crowd because people believed and listened.

"The Oracle was called Agbala, and people came from far and near to consult it. They came when misfortune dogged their steps or when they had a dispute with their neighbors. They came to discover what the future held for them or to consult the spirits of their departed fathers." (3.2-3)