M atthew Harvey Sanders still remembers how confusing it was to become Catholic. Raised Protestant, he became curious about Catholicism thanks to a high school crush and in college decided to convert. The process was grueling, filled with constant questions: Why do Catholics care so much about Mary? Why speak to saints instead of directly to God? Google often provided conflicting answers, and Sanders couldn't exactly call his priest every time a new question arose.

When ChatGPT launched in November 2022, Sanders saw a business opportunity in a conversational chatbot focused on helping people understand Catholicism. The following year, Sanders launched Magisterium AI, an LLM-based bot that can answer complex theological questions. The system relies on existing Gemini and GPT models, but is trained on over 32,000 Roman Catholic doctrines and teachings spanning 2,000 years.

“There's no way any priest would be able to have the information we have in our database inside of their heads,” says Sanders, 44. “Even the best theologians in the world, it’s not fair to expect them to act like a machine.”

Within three weeks of launch, Sanders noticed a surprising shift in user behavior. Though he’d originally built the product as a research tool for people interested in converting, students, scholars and priests, users began asking highly nuanced moral and personal questions. That pushed him to start developing his own Catholic AI model, Ephrem, expected to launch in 2027. The goal is for Ephrem to identify Church teachings and saints relevant to a user’s question, then suggest specific readings, prayers, habits or virtues to cultivate — what Sanders describes as putting a saint in your pocket.

The Catholic Church is increasingly taking a public role in the AI debate. This week, Pope Leo XIV presented his first major social encyclical—an official letter on moral and social issues—warning that AI is already reshaping human relationships, institutions and power. He criticized the use of AI in warfare, political manipulation and image distortion, and warned that the technology could become a new form of exploitation.

That concern is not limited to the Vatican. Anthropic, now valued at $965 billion, has been actively seeking religious input on how Claude should respond to moral and spiritual questions. In March, the company invited 15 Christian leaders to its San Francisco office to discuss how chatbots should handle personal questions, including those involving relationships, faith and self-harm. Anthropic cofounder Chris Olah, who is described as an atheist, spoke in Rome after the Pope presented the encyclical, saying AI is powerful, but poorly understood and in need of moral guidance.

For Sanders, this momentum has created an opening to build AI products within a Catholic framework. His background with religious technology dates back to 2015, when he first launched Longbeard, a web design startup that catered to Catholic organizations. Magisterium, which Sanders says has reached millions of people across 190 countries, is the company’s latest product. The chatbot makes money through a subscription-based pro tier and API access, with customers like Catholic prayer app Hallow. Sanders said Ephrem will likely follow a similar model.

Longbeard has raised $3 million to date across pre-seed and seed funding, according to Sanders, and is currently targeting another $4 million to $5 million in a Series A round at a $25 million valuation. That makes it very small, especially in the AI space. But its total addressable market is significant: There are roughly 1.5 billion Catholics globally. That was the bet for Patrick Gruhn, CEO and founder of fintech company Perpetuals.com and K-TV, the largest German-language Catholic television network, who invested $500,000 in Longbeard last March. Longbeard’s advantage, he says, is its access to Church documents and relationships that position Ephrem to become a trusted source of Catholic teachings in a time when people are turning to Claude or ChatGPT for answers.

Before starting Longbeard, Sanders served as an infantry officer in the Canadian military and briefly studied for the priesthood. In 2016, he began consulting for Catholic organizations and building relationships in Vatican City and across the Church. “We just started going to them and asking, ‘Can we have access to your library?’" Sanders says. He was well received: most institutions were eager to preserve old documents and increase accessibility to them. Longbeard would go on to digitize century-old books and provide tools to translate them into any language.

In November, the company hosted the second annual Builders Artificial Intelligence Forum at the Pontifical Gregorian University in Rome, drawing about 200 Catholic leaders and experts from 160 organizations (though no big AI companies). Pope Leo XIV did not attend, but he sent a formal message to the forum, urging AI developers to keep people at the center of their work.

Right now, Magisterium functions less like a chatbot for casual conversation and more like a “digital librarian,” says Michael Baggot, a Longbeard board member and professor of bioethics at the Pontifical University of St. Thomas Aquinas in Rome. But shifting it from more of a digital library tool into a conversational spiritual guide raises thorny moral questions, especially about how it handles topics like sexuality or abortion. Could such technology act as a substitute for a priest or a religious community? Should even priests be scared for their jobs?

“I think everyone's kind of struggling with this,” says Sister Nancy Usselmann, a Daughter of St. Paul and director of Pauline Media Studies in Los Angeles who attended Longbeard’s event in Rome. “We're all kind of working through it and it's okay. This is a good thing. We need each other to keep asking questions.”

She and her congregation, founded in Italy in 1915, have long been proponents of integrating religion and technology, opening offices throughout North America to help Catholic communities reach people through film, media and digital tools. But she noted Longbeard’s “saint in your pocket” concept raised concerns from its board members that making the tool feel too human could confuse users about what AI can realistically provide. To mitigate those risks, Baggot emphasized that if Ephrem lacks the context to answer a deeply nuanced spiritual question well, it will encourage users to talk to their priest.

“It's trying to be a Catholic version of ChatGPT,” she says. “A source where people can go to that is more reliable in its answers compared to OpenAI—I think it's really important that it's available for everyone.”

For Usselmann, it’s no surprise that mainstream tech leaders are turning to the Vatican for ethical guidance. Microsoft, IBM, Cisco, Meta, Google and Amazon have all been involved in conversations with the Vatican about AI safety and ethics. The Catholic Church, she argues, offers a central authority figure in the Pope and core teachings that have remained consistent over centuries. That’s the kind of steady moral weight that general artificial intelligence companies could use.