This is a difficult rating. I'm tempted to be tough on the movie because in comparison to some of Hollywood's best, this film doesn't make the first cut (unlike "The Passion of the Christ", which was absolutely first-rate through and through); HOWEVER, as a modern Hollywood take on a historical religious figure, I'm compelled to give it a "thumbs up". Typically, when Hollywood takes on a religious figure, and a Protestant one at that, you can usually safely assume the worst. Not so in this case. With that, I'm probably being swayed in the opposite direction if only because I'm so pleased to see a favorable portrayal of a famous Christian by Hollyweird however weak it really is. Take this into account when you read my review of "Luther" following...
Director Eric Till gives an evenhanded portrayal of Luther and the Roman Catholic church of his day. Contrary to what I expected, the Roman Church is not portrayed flatly, 2 dimensionally as a cartoon of perfect "evil" but is shown for what it was: in many ways corrupt, but also containing some who were sincere in their devotion to Christ. This was a welcome departure from the popular Catholicism bashing post the recent sex scandals. Johann Von Staupitz is positively rendered as not only a true friend of Luther's, but a real lover of the Truth and God's people. Katherine Von Bora, the escaped nun and later, Luther's wife, is depicted with all her famed spunk and character and is wonderfully acted by Claire Cox. And Peter Ustinov...well...he is as he often is: near genius at work in the complex portrayal of Frederick the Wise. (The best acting in the movie to me. I think I caught shades of "Prince John" from the animated Disney film, "Robin Hood", though.)
While Joseph Fiennes rendition of Luther is a bit too weak, too nervous, too manic for my taste, on the whole, he does capture the internal conflicts that Luther plainly experienced. It is a fact of history that Luther could swing from raging Reformer to doubting Thomas in a heartbeat, but most of his doubts were not of the truth itself, but of his fitness to champion it, being such a sinner as he saw himself to be. The film captures that. For sure, the movie does full justice to Luther's capacity for work! He is shown constantly engaged, either pen in hand, or preaching or teaching somewhere. I was a little disappointed though, that more of the earthy Luther wasn't shown, complete with jokes about breaking wind (Luther was heavily afflicted with gastric illness and kidney stones).
The main failing of the movie was that while the various characters continually made reference to Luther's "new" innovative doctrine, the movie scarcely scratched the surface of exactly what it was that Luther believed that was absolutely key to his drive to reform the Church. Those unfamiliar with Protestant history will only learn about the corrupt Roman Catholic practice of indulgences from this movie, but that was only one of several reasons Luther confronted the Roman Church. The main reason, "sola fide", salvation by "faith alone" was not given due explanation. To the degree that Luther's understanding of the Gospel vs. the Roman Church's teaching is not explained, to that degree the movie fails, because while it does focus on Luther, it avoids a detailed exploration of what made Luther, Luther. In my home we have the 10 volume collection of Luther's sermons. Reading through the very first of these, in the Church Postil (exposition of the Gospels) the ringing of the repeated note that salvation is by Jesus' sacrifice on the cross alone, and not mingled with any merit from either the Christian or the deceased saints is unmistakable. It's too bad the movie did such a slight treatment of the fundamental aspect of Luther's faith.
Despite the huge flaw just mentioned, I still think it's most definitely worth watching by the whole family (there is a brief scene of mutilation during the Peasant's War aftermath scene so some small children might be alarmed). Luther is positively portrayed as a sincere, brilliant, though sometimes conflicted giant of his day who more stumbled into starting a revolution than purposefully set out to "turn the world upside down." In my estimation, that IS the Luther of history.
If nothing else, if the film causes viewers to head to the local library to read up on Luther (consider the easy reading classic, "Here I Stand" by Roland Bainton), I think the movie will have done a great service for all-in-all.