My wife and I just saw this yesterday and we both thought it was amazing.

If you're not familiar with the story, it's the story of William Wilberforce (played very ably by Ioan Gruffudd) and his fight to abolish the British slave trade. (He also formed the SPCA, showing his compassion wasn't limited to two-legged animals.)

The supporting cast is outstanding and includes Albert Finney, Michael Gambon and Rufus Sewell. The title is from the hymn of the same name, written by an former slave ship captain (played by Finney) who s trying to atone for his sins against humanity.