Listen to the interview here.

Outspoken evangelical preacher Jim Wallis has been arrested many times at civil rights and anti-war protests over the years. In the wake of the deaths of Michael Brown, Eric Garner and Tamir Rice, he tells Andrew West it's time for America to confront its 'original sin'—racism.

Jim Wallis is a preacher par excellence who hates the pulpit. He prefers the streets, even more so when he's getting arrested, especially if it's outside the White House.

In the '80s, he protested against Ronald Reagan's cuts to anti-poverty programs and support for Central American military dictators. Twenty years later he was back, marching against George W. Bush's war in Iraq.

More recently, he's been at the doors of police headquarters in Ferguson, Missouri, joining with other prominent clergy to demand an end to what he calls the 'militarisation' of America's police.

The deaths of Michael Brown in Ferguson, Eric Garner in New York and Tamir Rice in Cleveland have also driven Wallis back to his desk to write his 10th book: America's Original Sin: Racism, White Privilege and the Bridge to a New America.

Wallis is the founder of Sojourners, a movement (and magazine) that for 45 years has been the heart of progressive evangelical Christianity in the United States. He met Barack Obama when the president was a community organiser on the south side of Chicago and advised him when he became an Illinois legislator.

They still talk periodically about the persistence of racism in America, even with a black president sits in the White House. 'We don't live in a post-racial society,' Wallis tells RN's Religion and Ethics Report.

'It does say that America is changing when Barack Obama is elected the president ... Demographics are changing and the biggest political fact in American life is that in two or three decades we will no longer be a white-majority nation.'

That fact frightens some older white voters, however, and explains—at least in part—the appeal and success of Donald Trump so far in the Republican presidential primaries.

Wallis believes that while Obama's presidency excited black and Democratic voters, the spate of black deaths in police custody has reawakened the country to the legacy of slavery and post-Civil War segregation. 

'There really are two criminal justice systems, and in one black lives don't matter,' he says.

'All lives don't matter, and won't matter, until black lives matter.'

The facts in Wallis's heavily footnoted book are confronting.  An African-American man has a 25 to 30 per cent likelihood of going to jail at some point; five times as many whites as blacks use drugs, but blacks are jailed for drug offences at 10 times the rate of whites.

'It's overwhelmingly racialised,' says Wallis.

'We have what I call America's original sin.'

Wallis says that just about every white American has benefited from the legacy of slavery—not intentionally, not even consciously, but simply because the economy was built on free labour for 250 years and exploited labour for 100 years after that.

Wallis the evangelical minister believes that at its core, racism is a sin of the worst order. It is evil to argue that the colour of one's skin changes the nature of one's relationship with God. 

'A long time ago we made a decision that we couldn't ... make into chattel property and thus create the biggest economic resource for building a new nation those who were made in the image of God.

'It's called Imago Dei. So we threw away Imago Dei—the image of God—and said they weren't fully human.'

Wallis hopes his latest book will challenge and help transform the last vestiges of such thinking.