Chapter Eighteen in this book describes the early life of the church in this tribe and its various trials and tribulations. Effectively, it gains a foothold through attracting those who are ignored and sidelined by the traditional Ibo culture and who are not allowed to "belong" in any way in their own society. Note what the clan think about this growth of the church:
The clan was worried, but not overmuch. If a gang of efulefu decided to live in the Evil Forest it was their own affair. When one came to think of it, the Evil Forest was a fithome for such undesirable people. It was true that they were rescuing twins from the bush, but they never brought them into the village.
"Efulefu" is a word denoting outcast or one who is not accepted within a society. The early church then gains a foothold in this society through firstly being given permission to build in the Evil Forest and then secondly attracting those who do not have any status or power in the Ibo culture. This is what allows them to grow and to gain in influence. Note too how the above quote indicates how immediately the church began challenging the Ibo culture, rescuing twins, who were said to be evil spirits.