Ben Affleck has spoken honestly about his "struggle" with belief and why he finds the teachings of Jesus "extremely powerful".

The actor and director spoke about his Christian faith in an interview with Beliefnet while promoting his new movie "The Way Back". 

In it, Affleck plays Jack Cunningham, who is down on his luck when he is offered a job coaching basketball at the Catholic high school where he was once a star player in his student days. 

The plot is close to Affleck's own real life struggles with alcohol, as Jack tries to put things right with the people he hurt as a result of his alcoholism. 

During the interview, Affleck spoke about how he "got introduced to Christianity a little bit later in life". 

The "Batman vs Superman" star became a Christian after his ex-wife Jennifer Garner invited him to church when her own faith was reinvigorated by her role in the 2016 movie "Miracles from Heaven".

Although they are now divorced, they remain close and are often seen attending church together with their three children. 

In 2018, Garner staged an intervention Bible in hand when Affleck's drinking spiralled, and drove him to a rehab facility. 

On Thursday, it was reported that she begged "The Way Back" director not to let Affleck go when he relapsed just before shooting was about to begin. 

Now sober, Affleck says he has found "beauty" in the Christian faith and especially the message of forgiveness and redemption. 

"One of the things that I found most beautiful about it, and I struggle with my faith, I struggle with belief, but I do see there's something enormously beautiful and elegant about the notion that we are all sinners, and that it's our job to find our redemption, to find God's love, to redeem ourselves, to live the best life that we can, to love one another, to not judge one another, and to forgive one another," he said.

He continued by saying that he found Jesus' teachings on forgiveness to be "extremely powerful ideas and very, very relevant, probably more relevant today than ever".

"Because there's a little bit more of an attitude of find something somebody did wrong once and get rid of them. And that to me feels unnecessarily judgmental. It's that 'he without sin cast the first stone.' I think that is a very wise proverb," he said.