Why did the white man use Christian tenets to force the native Americans to accept their ways?

Answer 1

First of, not all white people are Christian...

The reason this activity was prevalent in those times was because European churches would fund missionary activities. These activities ranged from religious indoctrination to religious/racial genocide. It is not a race issue though it was not 'white men" who did this, it was religious organizations, big difference here. These groups originated and were overtly controlled and funded by the religious orders.

Answer 2

The white man used Christian tenets to justify the imposition of their ways on Native Americans for a variety of reasons. One motive was cultural Imperialism, as they believed their civilization and religion were superior. They also sought to control and assimilate indigenous populations for political and economic reasons, often using religion as a tool to achieve these goals.