What tenet of native american culture and religion might have caused land and settlement disputes with white settlers?

Native Americans didn't have the same idea of land ownership that white settlers held. Native Americans held the idea of territory, but the idea that one could "own" the land was outside of their understanding of how the world works. 

Nature could not be owned.

Native American tribes believed land had its own spirit and could not be owned therefore could not be traded.

Whites believed land to be inanimate and could be owned, traded, and used whereas Native American religion believed nature held spirits and were alive as a person is alive. As whites attempted to sign treaties for land confusing occurred because Native Americans did not understand the transfer of land as whites did. This confusion over the process caused conflicts between whites and Native Americans. Native Americans were more willing to share the land but did not want to leave the land as the spirits of the land and the spirits of their ancestors lived in the land that whites wanted for resources.