According to Vittorio Messori, a major source of hostility towards Opus Dei is the application of political categories to a religious phenomenon such as Opus Dei. These groups against Opus Dei, he says, see everything happening in the world only through the prism of power-seeking, that is, of political spectrums of people in the left versus people on the right. Since Opus Dei is one of the major religious groups, the application of politically motivated campaigns against it is even stronger.