Belief in white Jesus linked to racism

[Belacqua]

So if someone says "This bit of information is not important and starts painting something inaccurate", I'm going to have to question the entire thing.

They modernized the appearance because the information they want to convey is very important. 

You have to decide what the message is and what meaning you want to get across. Is the historical accuracy of the clothing and hairstyles important to the message, or is the role of the characters in the moral story? Is Mary's hairstyle important, or her narrative role as a poor but worthy young woman?

As a non-religious example, think of the Tale of Genji. The author of that book makes it clear that Genji is the best-looking man of his generation. He's irresistible to women. But we know from documentary evidence that tastes have changed, and Genji probably looked a lot like Kim Jong Un. That is, he would not be attractive in the least to modern Japanese women. 

So if you're making a movie, you have to decide what message is important. Do you go with historical accuracy, and show Genji as a round little grotesque? Do you show the beautiful ladies of court with plucked-out eyebrows and big artificial ones painted high on their foreheads, so that they look ridiculous to modern audiences? (I think a modern audience would react by wondering "who in their right mind would fall for him?") Or do you get the best-looking actor you can, so that modern people react to him in the way that 11th century people reacted to Genji? If you're making a work of art with an emotional message, I think the latter is better. 

The devotio moderna movement thought that the important part was what role the characters played in their society, and that historically accurate visuals would not convey that emotionally to contemporary people. 

I think there are cases where modernization doesn't work. Recently Stephen Fry did a Picture of Dorian Gray set in our own time, with Dorian as an Instagram star. In my opinion this doesn't make Wilde's meaning more accessible to modern people, but less. The Dorian Gray of the novel was not a self-publicist, so I think Fry has completely changed the story's message. Giving Jesus a jet fighter would obviously change the meaning, as well.