Perry, who is the daughter of two California pastors, left home when she was 15-years-old to pursue her music career and got her big break in 2008 with the song I Kissed a Girl.
She said her mother Mary has always prayed that she would turn back to God.
"My mum has prayed for me my entire life, hoping I'd come back to God. I never left Him, I was just a little bit secular, I was more materialistic and more career-driven," she said.
"But now that I'm in my 30s, it's more about spirituality and heart wholeness."
Perry also talked about her huge love for Pope Francis.
"I'm such a big fan of Pope Francis. It's a combination of compassion, humility, sternness and refusal. He is rebel - a rebel for Jesus," she said.
Perry travelled to Rome last April to give speech about the health benefits of mediation at conference organised by the Pontifical Council for Culture.
She took her mother, who was raised Catholic, and actor Orlando Bloom with her.
"It started when we were on the Asia leg of the tour and I went to mass with my mum," the pop star said.
"She hadn't sung those songs in 40 years and watching her made me cry.
"It's so beautiful and humbling to re-centre in a place where it's not about anything else but reconnecting with the divine."
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