Is Iglesia ni Cristo’s Hostility Towards Other Religions Rooted in Doctrine or History?

With all the hostilities observed in the way members of the Iglesia ni Cristo act towards non-members of their church, was it always a part of INC doctrine to be antagonistic toward members of the Catholic Church and other religions?

Or does this hostility stem from a justified event of suppression or oppression during their early existence?

It seems plausible that the predominantly Catholic, fundamentalist Filipinos of the past may have been antagonistic toward this church, which could have been perceived as a sect, but idk lol.