Non-believers should challenge us to think about our faith more deeply, the UK's former chief rabbi has said, noting that he enjoys a great relationship with staunch atheists such as Richard Dawkins.

Speaking to HuffPost Live, Jonathan Sacks said it's vital that we accept those who think differently to us.

"You have to acknowledge that you are secure in the fact that God loves you, but he doesn't have to love anyone else just because they're not like you, that's not what God is about," he said.

"I believe...in the dignity of difference. We're each different which means we each have something unique, and God loves us for that which is unique in each of us."

Sacks went on to say that he has a "wonderful friendship" with Richard Dawkins and popular science author Steven Pinker.

"I love them, I call them his majesty's loyal opposition. I don't know if that phrase translates into America, but you get the point," he said.

"Why did God invent atheists? Answer: to stop religious leaders from getting too big-headed, to challenge us.

"'If God exists, how come there's so much suffering in the world?' An atheist tells me that and I can't sleep at night, because it's a good and valid point. But the truth is, you don't have to be an atheist to say that, because Abraham and Moses also said it."

Sacks concluded: "I really do respect them, and I think they have something very important to teach us in the 21st century: the secularisation of power. An atheist reminds us of a fundamental truth: never give a religious leader power, we just don't know what to do with it.

"I think atheism is there and a serious part of this conversation, I just wish sometimes they'd be a little more gracious about it that's all."