It would have been easy for the makers of the film “Amazing Grace” to sidestep faith in telling the story of William Wilberforce, the man who led the fight in Parliament to end slavery in Great Britain.

But Wilberforce’s Christianity was the driving force behind all his work in politics, and it would have been inaccurate to brush over or ignore it.

Director Michael Apted and screenwriter Steven Knight, however, make Wilberforce’s faith central to the story without becoming preachy or self-righteous. They and Welsh actor Ioan Gruffudd bring to life a man who lives his faith every moment of every day. “Amazing Grace” also shows the toll Wilberforce’s long fight to end slavery took on his body and the weight it foisted on his soul.

Wilberforce was born to a wealthy merchant in 1759 and flirted with evangelical Anglicanism in his teens. He was elected to the House of Commons along with his friend William Pitt in 1780. Five years later, he had what he described as a “conversion experience” and questioned whether to stay in politics or to become a minister.

His abolitionist friends encouraged him to stay in Parliament, saying, “You don’t have to choose between God and serving in the public square. You can do both at the same time.” The Rev. John Newton, the former slave-ship captain-turned-preacher who wrote the hymn “Amazing Grace” successfully urged Wilberforce to take up the yoke of slavery.

The filmmakers intricately weave the Christian ideals behind the anti-slavery movement with the political realities required to end the slave trade. They also adeptly portray how the revolutions in the North American colonies and in France, along with the Napoleonic Wars, delayed action on the bills Wilberforce continued to introduce as he struggled with ill health.

Some of the story is told in flashback and occasionally it is not immediately clear where in time the story is taking place. That is a minor flaw in an otherwise fine but decidedly old-fashioned biopic.

Gruffuddd, best known in the U.S. as Mr. Fantastic in “The Fantastic Four,” is delightful as Wilberforce. He brings to life the man’s battle to end slavery and the physical toll it exacts without ever stepping over the line into bravado or self-pity. The Welsh actor’s performance is the heart of the film.

Albert Finney, who portrays the Rev. John Newton, is its soul. Wilberforce first met Newton as a child, when he attended a church where the former slave-ship captain was a rector. The two met again when Wilberforce was in his 20s.

“William, there are two things in my life that I know: I am a great sinner, and Jesus Christ is a greater savior,” Newton tells his protege. Finney makes the man’s guilt over his complicity in the slave trade palpable. The depth of the actor’s performance is astounding. Without it, the film would not be as moving and compelling as it is.

The entire cast of British actors, many of whom will look and sound familiar to “Masterpiece Theater” fans, bring the latter half of the 18th century to life in all its opulence and inhumanity.

“Amazing Grace” is a fine addition to the legacy of Wilberforce, which includes Wilberforce University in Wilberforce, Ohio, the first university founded and owned by African Americans.

The film is rated PG for thematic material involving slavery and some mild language.