One of the world’s raunchiest rock stars, Prince is in his stacked heels and flamboyant suit strutting from house to house around an ordinary suburban estate.

Flanked by minders, he goes up a garden path, knocks on a door and politely asks the householder: “Would you like to talk about God?”

It’s an extraordinary image. You can only imagine the shock of a ­homeowner finding the superstar on their doorstep clutching a bible and delivering a message about the divine.

Can this really be the same man who shot to fame with outrageously explicit songs such as Sexy MF?

Prince admits his door-to-door missions as a Jehovah’s Witness raises eyebrows. “Sometimes people act surprised but mostly they’re really cool about it.

Sometimes he tries to escape his fame by going in disguise. He says: “My hair is capable of doing a lot of different things. I don’t always look like this.”

You only have to meet Prince for a few minutes to realise the extent to which God – rather than the colour purple – now influences how he lives.

Much of what he says, as well as his songwriting, revolves around his beliefs these days. Even the mysterious numbers he slots into his material are thought to be coded biblical references.

I join Prince at his Paisley Park base near his home city of Minneapolis in the US Midwest.

It is days before his eagerly anticipated new album 20TEN is released free inside this Saturday’s Daily Mirror in the biggest music giveaway of the year.

In my view it’s his best record since his brilliant Sign o’ the Times and, with ­references from “fat bankers” to melting ice caps, it’s his most socially aware.

The songs – and even his ­decision to give them away free to Mirror readers – have been influenced by his faith.

He says: “It’s great to give away my music through your ­newspaper. God is a generous and loving being. It is written that we should act like God. There are enough opportunities.”

The Knowledge Room

On my guided tour of Paisley Park it’s clear that for Prince the most important part of the 70,000 sq ft complex isn’t the recording studio where he’s created hit after ­worldwide hit but a peaceful ­sanctuary on the first floor which he calls The ­Knowledge Room.

Lined with shelves of religious ­literature, it’s where he contemplates the meaning of life, prays and studies the Bible for up to six hours a day, sometimes long into the night.

The teetotal vegan, a youthful-looking 52, is certain his faith has changed his life.

He says: “There’s an incredible peace in my life now and I’m trying to share it with people.”

He talks with a real missionary zeal though some of his comments are puzzling. At one point he says: “You know there are bad angels as well as good angels.”

It reminded me that he once revealed he had epileptic seizures when he was young – until “my mother told me one day I had said to her, ‘Mom I’m not going to be sick any more because an angel told me so.’”

I ask him about the story. He thinks for a moment and then says: “I never talk about the past.”

Subject closed.

He avoids performing his most X-rated sexual material from the 80s and early 90s – those massive selling songs such as Gett Off – and cautions against swearing because “you call up all the anger”.

He is also known to donate huge chunks of his £100million fortune to good causes around the world. And, perhaps most surprising of all, the man who was romantically linked to beauties including Sheena Easton, Kim Basinger and Carmen Electra – and sang about “23 positions in a one night stand” – is a fan of monogamy.

He’s been dating ­stunning singer Bria Valente, who is almost half his age, for at least three years.

For Prince that’s no small feat!

It is believed that, like his second wife Manuela Testolini, who he divorced in 2006, Bria has become a Jehovah’s Witness, has been baptised in a pool and attends regular Bible studies at their local Kingdom Hall meeting place.

Tragedies put wild life behind him

The background to why he ­abandoned a world of hedonistic excess can be traced to a series of tragedies in the mid to late 90s.

It was a time when his glittering career seemed to be faltering and contractual frustrations with his then record company Warners were boiling over.

He replaced his name with an unpronounceable symbol, became the Artist Formerly Known As Prince and scrawled SLAVE on his cheek.

But all that paled beside the anguish of the death of his baby son Gregory in 1996.

Prince had set his heart on starting a family with his first wife, dancer Mayte Garcia.

Seven days after their child was born the child died from a genetic disorder of the skull called Pfieffer syndrome.

More heartbreak and soul-searching followed with the death of both the star’s parents.

Dad John L Nelson was a pianist and bandleader.

Prince’s mother, the jazz singer Mattie Shaw, died six months later. Her final wish was said to be that her son should become a Jehovah’s Witness as she had been for most of her life. Prince grappled with depression and something approaching a midlife crisis.

To the outside world he was a gleaming example of the American Dream.

Prince Rogers Nelson, an African-American boy from a broken home on the wrong side of the tracks who had faced down the bullies at school and every other obstacle to conquer the world with truly ­innovative music.

A rock legend who had amassed a fortune from global tours and sales of more than 100 million albums, including classics such as Purple Rain, 1999 and Diamonds and Pearls.

And when he wasn’t making music, he was picking up beautiful women or awards including Grammys and even an Oscar.

But for Prince all the dizzying success meant little. As he searched for purpose to his life he became friends with one of his heroes – former Sly and the Family Stone bassist Larry Graham, now 63.

A committed Jehovah's Witness

The soul veteran made a huge ­impression on Prince, telling him how he had recovered from a life of drugs and violence by being born again as a Jehovah’s Witness. Larry convinced him to convert.

Prince says: “Larry goes door to door to tell people the truth about God. “That’s why I told myself I need to know a man like him. He’s a friend who calls me his baby brother.”

Larry says: “Prince is a spiritual man. Sometimes we study for hours – six, seven, eight hours a day. We sit down and get into the scriptures.”

Prince’s place of worship is the Chanhassen Congregation, a few miles from Paisley Park.

One of the elders there says: “We have watched Prince since he started studying the Bible and noticed a dramatic change. We go on Bible studies together and work in field service, the door-to-door ministry that Jehovah’s Witnesses are known for.

“When people being called on get past the initial shock of actually meeting Prince, he is very persuasive. He uses the ­scriptures very well.”

Critics claim it has led to him adopting surprisingly hardline conservative views on issues such as gay marriage and ­abortion.

In one interview two years ago, he was quoted as saying: “God came to earth and saw people sticking it wherever and doing it with whatever, and he just cleared it all out.

“He was like, ‘Enough.’”

Prince denied taking such a stance and is now careful not be drawn on his beliefs.

“I can give you books to read and you would understand,” he says, “But I ain’t going into details with you.”

I ask does he regret the wild image which helped catapult him to fame all those years ago? The dirty lyrics, ­endorsements of casual sex, the nude figure on the cover of Lovesexy?

He thinks, smiles and in typically Prince style says: “I live in the here and now. You should try it too.”