The key to interpreting the film is given in the quotation from W. Durant words that first appear on the screen: "A great civilization is not conquered from without until it has destroyed itself from within." These days a revisionist reading of the Spanish Conquest of South America is very much in vogue. We have gone from Spanish Conquistadores taking the great benefits civilisation and Christianity to a reading of history that exalts the previous civilisations and associates Christianity with European imperialism imposed upon a noble people. This is now so widespread that recently we were even treated to the spectacle of a newly elected South American president sacrificing to the pagan gods before taking office!
In Apocalypto Gibson is challenging this romantic and fanciful reinterpretation. The Spanish when they appear seem to carry no weapons. There is only a friar bearing a Cross. The Mayans are the ones practising human sacrifice. Gibson juxtaposes two civilisations without comment leaving us to ask whether what is symbolised by the Cross is truly worse than the cult of the Sun?