Why was the white man a devil, acording to the Muslims?

The people of Islam saw the whites as devils because they sought the white people as rulers that takes advantage of anybody who is not of their race. They oppressed the black men as what the blacks thought was "self defense" in conflictual activities was actually of harm to the white individuals, due to the fact that they tend to take things falsely. While Malcolm was in prison, he reminisced the days of when the white individuals have taken advantage of him and showed him the wrong path, which eventually lead him to the position he was in.