Mel Gibson is an ardent member of the "Latin rite" Catholics, an ultra-conservative Catholic group who border on schismatics that reject the reforms wrought by Roman Catholic Church's Vatican II Council of the late 1960's.
It is sublimely ironic that the Passion's defenders and main media market are those fundamentalist and evangelical Protestant christians, most of whom are anti-ecumenical, utterly anti-Catholic (e.g. Bob Jones university et al) and as doctrine regard Gibson's Roman Catholic Church (Latin Rite or not) as the "Whore of Babylon" and the Pope himself as the "Antichrist."
You speak entirely too broad.
Yes, there exists a particular strain of evangelicals who consider Catholicism as you say, particularly the version which Gibson's father adheres.
But 99% of evangelicals do not. And it is those who are defending this film, because those who have seen it have said it is a good film that depicts the crucifiction faithfully as described within the Bible.
I think you might have some issues you should get resolved, rather than trying to turn Christians against each other.