Why do the clan decide to grant the request of the missionaries and give them some land on which to build a church?

In chapter 17, the missionaries arrive in Umuofia and ask for a plot of land to build their church. The village elders do not want the missionaries near the clan and decide to offer them a plot of land located in the Evil Forest. The Evil Forest is a forbidden, ominous place, where the clan buries individuals with diseases and is also used as the dumping ground for the powerful medicine men when they die. According to the villagers, the Evil Forest is a wicked, sinister place, where powerful dark spirits dwell, which is why they allow the missionaries to have as much land as they want. The villagers believe that they are harming the missionaries by offering them such a wicked plot of land and laugh at the missionaries, who appreciate the offer. Initially, the villagers believe that the missionaries will not survive more than four days in the Evil Forest and are shocked when none of the missionaries die after the first week. As time passes and the missionaries continue to survive in the Evil Forest, the villagers believe that the white men have extremely powerful magic that allows them to speak to evil spirits and survive in the forest.