Joe Biden says church is a "safe place" he enjoys going to because it gives him time to "be alone".
The US president - only the second Catholic to hold office after John F Kennedy - talked about his faith in a recent interview with People magazine.
He said he never misses mass and that prayer is an important part of his faith.
"I don't want to proselytize. My religion, for me, is a safe place," he said.
"I never miss mass, because I can be alone.
"I mean, I'm with my family, but just kind of absorbing the fundamental principle that you've got to treat everyone with dignity."
He said his wife Jill leaves inspirational messages for him on the mirror to read when he shaves. One that he especially enjoyed was the "great quote" from Danish philosopher and theologian Soren Kierkegaard - "Faith sees best in the dark."
"Other people may meditate. For me, prayer gives me hope, and it centers me," Biden said.
Despite his personal commitment to his faith, Biden has angered Catholic leaders over his abortion stance.
Last month, Catholic bishops in the US criticized his decision to restore federal funding to abortion providers like Planned Parenthood and Marie Stopes International.
"It is the policy of my administration to support women's and girls' sexual and reproductive health and rights in the United States, as well as globally," said Biden in the memorandum.
"These excessive conditions on foreign and development assistance undermine the United States' efforts to advance gender equality globally by restricting our ability to support women's health and programs that prevent and respond to gender-based violence."
