Since seeing the film and discussing it with others, Christians (both Catholic and Protestant) in particular, I’ve been a bit surprised at how many people believe that the events actually happened as depicted. That is, they believe that the depiction is Biblically accurate.
It is not. In fact, it’s way, way off in many respects. However, according to those who have read her works, the film does indeed accurately reflect the “revelations” of a 19th century German nun, Anne Catherine Emmerich (1774-1824). Her book, The Dolorous Passion of Our Lord Jesus Christ, was published by the church in 1833. Current edditions of this book claim that it is the inspiration behind Gibson’s The Passion of the Christ.
For what it’s worth, I think it’s important to make distinctions between dramatizations (which have certainly been done many times in film with respect to Biblical events) and that which is claimed to be literally true. Gibson claims that he believes this film to be literally true, and if you believe that as well, then you should know that these “truths” are not found in the Bible, but in the mystical “visions” of someone who lived 200 years ago and some 1800 years after Jesus Christ.
There is a somewhat lengthy, but well-researched article about all of this, and much more. Read it here.