At a Protestant church in Germany, hundreds gather before a screen set up above the altar as artificial intelligence-powered service begins. An avatar pastor delivers the sermon, and worshippers stand and sit in unison after prayers, following the digital preacher’s lead.

This is not a scene from a sci-fi movie -- it is a real church service that took place at St. Paul’s Church in the German town of Fuerth in June 2023.

Artificial Intelligence technology is transforming industries and even religion -- a domain once thought to be deeply human and spiritual. Amid mixed reactions to AI’s impact on faith and religious practices, churches and temples are introducing "AI Jesus" and "AI Buddha" to answer the pressing question: Will AI become a faithful tool for spiritual growth, or a force to threaten the existence of God?

In Seoul, a team of researchers set up an AI shrine in December 2024 to find out how people perceive and interact with an AI-generated spiritual being.

Colorful ribbons, candles and bells filled the dimly lit space, creating a ritualistic atmosphere. An invisible shaman, speaking in the voice of a middle-aged woman, offered fortune-telling and comforting words as visitors entered their birthdates into a tablet PC and shared their worries, seeking advice.

“While we could not confirm whether it evoked true religious faith, we found that people first engaged with the AI shaman lightly, and gradually shared deeper concerns and sought serious advice,” Nam Tek-jin, an industrial design professor at Korea Advanced Institute of Science and Technology who led the experiment, told The Korea Herald.

The project, dubbed “ShamAIn,” inspired by Korean Shamanism, used OpenAI’s application programming interface but did not specifically train on fortune-telling databases. Its results will be presented at this year’s Computer-Human Interaction Symposium slated for April.

“Many participants said they experienced psychological comforting and received meaningful guidance on their concerns,” Nam said.

With moving avatars and voices and texts delivered in natural language, it appears that people are open to accepting AI-generated figures, and even trust their thoughts.

When a Swiss church installed an AI-powered Jesus capable of conversing in 100 different languages inside a confessional booth last August, similar observations were made.

Designed with the avatar and the voice of a young man, the AI Jesus interacted with more than 1,000 believers over two months as part of an experiment conducted in collaboration with Peterskapelle Church in Lucerne and the Immersive Realities Research Lab at the Lucerne University of Applied Sciences and Arts.

While the experiment sparked heated debate, more than two-thirds of 230 users who gave feedback said their interaction with the AI was a “spiritual experience.”

According to Philipp Haslbauer, a member of the research lab, the conversations between believers and AI Jesus touched on critical and sensitive topics, from “Why isn’t a woman a priest?” to love, sexuality, death and the afterlife.

The perception of AI’s presence in religion, however, varies sharply, with critics seeing it as a disruption that undermines religious traditions.

The AI Jesus at the Swiss church was called “blasphemous” or the “work of the devil” in online comments.

“This is, simply put, blasphemy and goes against the Bible. It feels insulting. Don’t let this be the start of accepting AI in places like this,” a traveler posted on Tripadvisor in his review of AI Jesus at the Lucerne church.

The opposition believes AI clergy lack true spirituality and divine authority and worries that AI-driven services could reduce worship.

There are also concerns that misinformation and theological bias can be created with the “imperfect” technology.

Nam of KAIST found in his research that people tended to “blindly” trust what AI said, possibly because their beliefs are largely influenced by their desires.

Pope Francis has also warned about the potential dangers of AI after a fake image of him wearing a large white puffer coat went viral. Calling the technology “exciting and disorienting,” the Pope urged the creation of an international treaty to ensure the ethical use of AI technology.

AI also caused a stir in 2017, when Anthony Levandowski, a former Google and Uber engineer, launched the religion Way of the Future, which upholds the "realization, acceptance and worship of a Godhead based on AI developed through computer hardware and software."

While the service ended shortly after launch, Levandowski announced a revival of the AI church in late 2023, saying it has garnered a congregation of "a couple thousand people." He believes AI has the potential to bring "heaven on Earth."

Clergy and engineers in Korea are actively experimenting with AI to explore its impact on religion, recognizing it is an "inevitable trend" that will settle in the future.

With hopes of developing AI as a spiritual guide to support daily religious practices, religious authorities are introducing AI-powered apps. They include AI Buddhist counseling bots and AI monks as well as Christian apps like Chowon, which is trained on the Bible. Bongeunsa Temple in Seoul has also utilized AI to generate video clips featuring an avatar resembling a monk delivering Buddhist teachings.

These mobile apps incorporating AI offer daily sermon sessions and run chatbots that answer questions ranging from personal difficulties to existential concerns about life and death, drawing from religious teachings.

Ma Sang-uk, a pastor and the head of an AI education research institute, sees AI not as an intruder into the spiritual realm, but as a "speaking library," a tool for religious education and guidance.

“I believe AI may extend into the realm of the heart, offering counseling and responses based on patterns. But in the realm of the soul, which involves intuition, spirituality and encounters with the divine, AI has no place,” Ma said.

“AI lacks the deeply human qualities needed for higher-level creativity, spiritual experiences and the capacity to love."

Ma emphasized that the technology would more likely become a tool to assist clergies rather than replace them, and that religions should embrace it for the education of the future generation.

“I personally don’t believe people will worship AI technology as a divine entity. But AI might fulfill some of the roles of religion, which include providing mental support and well-being,” Nam said.

He added that AI could act as a mediator between individuals and their religious beliefs.

“The changes AI will bring to the world will require us to make difficult choices and manage conflicting ethical demands," Venerable Boil at Haeinsa Temple said. "The growing tension between religious ethics and the laws and institutions that represent the interests of AI-driven capital and corporations will only intensify."

While opinions remain divided, experiments continue as religious communities seek to understand and adapt to the emerging technology.