TELEVANGELIST JOEL OSTEEN’s teenage daughter is obsessed with sexy pop star KATY PERRY – and a source says he’s terrified it will lead to his girl rebelling against the church!

Texas-based Osteen’s 14-year-old daughter Alexandra plays a central role in her dad’s televised services, showcas­ing her singing talents on the coast-to-coast broadcasts.

But she’s said to adore Katy’s songs and reli­giously follows her on Twitter, and now insid­ers fear that the teen will wind up just like the sexy songstress, who’s also a preacher’s daughter.

“The parallels between them are hard to ignore,” a source told The ENQUIRER.

“Like Alexandra, Katy grew up in an extremely religious household and began as a gospel singer in her father’s church. But when she decided on a music career, she com­pletely rebelled.”

As for Alexandra’s parents, Joel, 50, and his 52-year-old wife Victoria – who have been married for 26 years – they don’t want anyone shaking up their $40 million empire.

“Joel is worried that Alex­andra’s obsession with Katy’s music could ruin his image and strain his family relations,” said the source. “He also fears she’ll try to follow in Katy’s footsteps.”

Katy released one Christian rock album before destroying her pious image with her scan­dalous debut single, “I Kissed a Girl.” Once famous, she capi­talized on her bombshell looks, appearing on the cover of “Maxim” magazine in lingerie and releasing a music video in which whipped cream shoots from her breasts. She also married and divorced British bad boy actor Russell Brand. Katy, who turns 29 this month, is now dat­ing playboy rocker John Mayer.

During a sermon, Katy’s disappointed dad reportedly blasted her as a “devil child.”

“Katy has completely let her religious values fall by the way­side,” said the source. “Joel is panicking that as Alexandra gets older, she could do the same.”