Christian faith should lead to action carried out consistent with that faith (compare the abolitionist leaders of Britain to those of the U.S.) .
Young adults (under 30) can be principled and mature, and when they are, they effect powerful change in the life of others much older.
A pastor can have a life-long effect on the youth that he pastors (John Newton was William Wilberforce's pastor as a boy)
The actor who played John Newton was very powerful
There were a couple of things I didn't like:
From what I understand of Wilberforce's life, the movie should have had even more of an emphasis on Christianity as the cause for ending the slave trade in Britain.
Hollywood continues the myth that immodest dress is required for a woman to be attractive.