The main idea of Paragraph 9 is that the churches have not provided Black protesters and civil rights activists any support, even though it is Black people who pray in these churches.
The main idea of Paragraph 10 is that the Church is no longer a revolutionary force, but instead a supporter of the status quo and the most common power structure.
The effect of making these points in this order is that King brings attention to the fact that the Church has been extremely ineffectual in causing or encouraging any change in society. King reminds us both of the past and the present Church, and he shows how the Church has sided with the oppressors, and not with the oppressed.