Even before any music plays on Madonna’s thundering 1989 hit, “Like A Prayer,” which sat atop the pop charts for 16 weeks, we hear the Material Girl’s plaintive voice asking a simple question:

“God?”

It’s one the pop star has been raising, in some form or another, for years. Religion has been a favored subject for Madonna since she got her start in the music business more than three decades ago, whether she’s appropriating Roman Catholic iconography in a music video or dabbling in Jewish spiritual traditions.

And her upcoming tour, kicking off Sept. 9 in Montreal to promote her new album, “Rebel Heart,” will be no exception.

“I’m very immersed in deconstructing the concept of sexuality and religion and how it’s not supposed to go together, but in my world it goes together,” the superstar told guest editor Andy Cohen in an upcoming issue of Entertainment Weekly.

The idea promises to be big business. Madonna’s last two world tours ranked among the top 12 highest-grossing tours of all time. Her 2008 "Sticky & Sweet" tour grossed $408 million, while the 2012 "MDNA" tour earned $305 million. For that, she can thank longevity, a keen knack for being able to reinvent herself, and a cross-generational fan base that stretches throughout much of the world. In 2012, the pop queen famously outsold Lady Gaga during a number of tour stops in South America while the two stars were feuding.

Devilish Divinity

In speaking about the religious concepts in her latest tour, the 56-year-old Madonna was referring specifically to the nuns dancing provocatively on poles in a teaser video posted to YouTube, but she might as well have been alluding to entire swathes of her pop canon. Madonna’s flirtation with religion in her pop culture persona began when she popularized donning large crosses and rosaries -- the latter of which is frowned upon by the Roman Catholic Church -- as a fashion statement in the 1980s.

But the flirtation turned into a full-on affair with Madonna’s seminal “Like A Prayer” album in 1989. The video for the single by the same name told the story of a young white girl in a forbidden interracial relationship, but it also featured a heavy dosage of Catholic iconography.

The skimpily clad Madonna danced on screen in front of burning crosses and made love to a saint, all while bearing the scars of stigmata on her hands. The Vatican was not amused, calling the video heresy and demanding that it be banned. Pepsi, which had entered into a lucrative endorsement deal with the singer, backed out of the contract and canceled a commercial in which she debuted the song.

“Like A Prayer” seemed to launch Madonna’s penchant for pushing traditional religious buttons. Other songs on the album included “Spanish Eyes,” which voices skepticism about God’s existence (“And if there is a Christ, he’ll come tonight/To pray for Spanish eyes”) and “Act of Contrition,” which seemingly mocks traditional forms of repentance.

She poked the Vatican again in 2006, when she staged a mock crucifixion at a concert in Rome, ignoring the flurry of protests and condemnations from the Vatican.

Sex And The Soul

Madonna’s own spiritual background has taken as many twists and turns as her music career. Hailing from a Catholic family in Michigan, the Queen of Pop began dabbling in eastern mysticism and Kabbalah, a Jewish school of thought, in the late 1990s, after the birth of her daughter, Lourdes.

That influence soon wended its way into her work, as well. In the 2002 music video for “Die Another Day,” a song for the James Bond film, Madonna is seen as a prisoner in a torture chamber. The video also uses Jewish texts and sacred objects. Unsurprisingly, many scholars of Judaism declared the video as sacrilegious.

But in a March interview with the Irish Independent, the singer clarified her personal religious views.

“I don't affiliate myself with any specific religious group. I connect to different ritualistic aspects of different belief systems, and I see the connecting thread between all religious beliefs. I have not converted to Judaism,” she said.

And despite the fact that she studied Kabbalah, reads the Torah on Saturdays and observes Shabbat, Madonna said those rituals “are connected to what I describe as the Tree of Life consciousness and have more to do with the idea of being an Israelite, not Jewish.”

The singer added that her spiritual beliefs encompass many religions: “And I believe what I practice has to do with something deeper than religion, that it embodies all religions, including Judaism. And Christianity. And Islam.”

But she made one thing clear: She firmly believes in the idea that sexuality and spirituality go hand in hand.

“There's no law that says that you cannot be a spiritual person and a sexual person. In fact, if you have the right consciousness, sex is like a prayer,” Madonna told the Independent. “It can be a divine experience. So why do they have to be disassociated with one another?”