Last time I noted some thoughts from Paul Hiebert’s Transforming Worldviews about the dualism that grew up in Western culture over the last few centuries, the separation between religious and secular life.
Hiebert also noted the effect this had on missions:
In missions this dualism has led to a division between “evangelism” and “social gospel,” reinforcing the dualism that led to the secularization of modern societies. For many people, evangelism concerns the super salvation of the soul, and the social gospel involves ministry to human physical needs, such as food, medicine, and education. Missionaries planted churches and built schools and hospitals. They saw their task as Christianizing and civilizing people. The two endeavors were often seen as separate tasks. (Kindle location 3164)
As Hiebert noted, when societies rejected Christianity but accepted the social aspects, modern missions became one of the world’s great secularizing forces. He also notes:
Modern dualism also led many missionaries to deny the reality of spirits, magic, witchcraft, divination, and evil eye, which were important in the everyday life of the people they served. Young Christians in these communities kept their beliefs in these this-worldly spiritual realities but hid them from the missionaries because the missionaries did not believe in such phenomena. The result was “split-level” Christianity in which young Christians were Christian in public, going to church and reciting the confessions on Sunday, but were traditional religionists in private, turning to magicians, diviners, and shamans during the week. (Kindle location 3173)
So what happened in many places was a superficial acceptance of Christianity, a wholesale acceptance of Western social structures, and an underlying continuance of traditional beliefs. In order to get the schools and hospitals, they were willing to perform Christian rituals, but their hearts remained unchanged.
By not changing underlying worldviews (including their own), missionaries failed to actually convert those they dealt with.
Obviously, Hiebert is painting with a broad stroke. Exceptions abound. But in far too many places, this is exactly what took place.
On Friday, I posted a link to 
I’m finally reading Paul Hiebert’s Transforming Worldviews: An Anthropological Understanding of How People Change. Hiebert was a pioneer in the field of missionary anthropology. I had looked at the book a few years ago when searching for a textbook for a sophomore level missions class. I saw that the book addressed the themes of the class, but that it was too advanced for sophomores.