Many of the Native Americans did take up the Christian religion for the sake of self preservation. Believe or be culled.
There are many, many such examples. My own family contains one such example. A distant relative was capture by Christians and held for ransom. Eventually, after years of captivity she converted to Christianity and married one of her captors.
We often hear that Islam was spread by the sword. Christianity was most certainly spread by the sword and a vast number of Christians accepted the religion only for that very reason. In addition, unlike Islam that not only allowed but encouraged conquered people to retain their own National Identity, Religions and Cultures, Christianity usually set out immediately to destroy and obliterate any evidence, knowledge or remnants of such Identity, Religion or Culture.
This is why I believe that anyone who considers himself or herself as a Christian should be aware of both the good and bad that's been done. Unless we know and understand such things we will continue to practice them. Those who forget history will relive it.
Aslan is not a Tame Lion