Bob Marley Always Traveled with a Bible, Recalls Photographer Friend: He Was 'Really Reflective' (Exclusive)

Bob Marley, who would have turned 79 on Tuesday, was more than just the world's most famous reggae artist. According to photographer Kate Simon, who traveled with Marley to shoot his 1977 European tour, he was also deeply religious.

"On the tour bus, he'd be really reflective," Simon tells PEOPLE, noting that he preferred to sit alone on the bus, either strumming his guitar or reading his Bible. "Even in the airports, he read the Bible. He had a little travel Bible that he brought with him everywhere. I have pictures of him reading it."

Simon, whose book of Marley photos, Rebel Music: Bob Marley & Roots Reggae, was re-released from Genesis Publications in November, says she believes his spirituality is why his music is just as popular today as it was when it was first released.

"He was extremely intelligent," she says. "He sang about the universal thoughts and feelings and ideas. He would talk about interdependence and humanity, and how we needed each other to survive. He would also spread a message about love, but also about standing up for your rights. He was a real teacher."

She adds, "He was also very disciplined. He'd always be the first one on the tour bus and at soundcheck before the show. He was very serious about his music, and about everyone around him."

However, Simon points out that Marley wasn't just soft-spoken and serious — she says his charisma was unrivaled.

"I had brothers and he used to razz me like they did," Simon says. "He just had this beautiful way about him. Everyone wanted to be around Bob."

Marley died of cancer in 1981 at age 36. His life is set to get the biopic treatment on Feb. 14 with the release of Bob Marley: One Love, which stars Kingsley Ben-Adir as the reggae legend.