Éric Célérier on Hello Bible and Building a Christian LLM

Éric Célérier believes AI is this generation's Gutenberg moment for the Bible, and he's building an open-source Christian language model so the whole church can use it.

Éric is a French pastor, theologian and technologist who has used digital tools to make Jesus known for more than two decades. He built one of the first church websites in 1997, founded the global Jesus.net movement, serves in a strategy role with The Chosen, and now leads Hello Bible, an AI-powered Bible companion.

We sat down with Éric at Missional AI 2025 in Dallas to hear how a lost dog led him to AI, how he built Hello Bible, and why he thinks the church needs its own aligned AI model.

How The Chosen came to French national TV

A season of fasting and prayer led Éric's media group to bring The Chosen to French national television, and from there to help shape the series' global distribution.

Each year, Éric fasts and prays with the board of his media group, a foundation of around twenty companies, to discern their next step. During one of those times, a friend in the US urged him to watch The Chosen, then only in its first season. The board watched it together and prayed for two things they had no idea how to get: the rights, and a slot on national TV.

A few months later, they had both. When The Chosen's team heard what was happening, they held their first premiere outside the US in France. Jonathan Roumie came and became a good friend. The team then asked Éric to help write a global distribution strategy, which they went on to deploy.

From a 1997 website to Jesus.net

Éric's digital ministry began with hand-coded HTML and grew into a global movement.

In 1997 he built a basic website for the church he was planting. During a time of prayer, he received the idea for a step-by-step online presentation of the gospel. That site grew into Jesus.net, a movement of organizations across many countries using the internet, media and social networks to help people know Jesus.

In 2009, just before buying the Jesus.net domain, Éric was in Dallas. At a church there, an 84-year-old man prayed over him with a word from the Lord: he would make Jesus famous throughout the world. The domain was so expensive that a friend joked they could have bought two Porsches instead. Éric bought it anyway.

"God was in the dog"

Sixteen years ago, a lost dog in Dallas led Éric to imagine AI-powered Bible answers years before ChatGPT existed.

The dog belonged to Raúl García, who lived in Addison, near Dallas. A friend of Éric's found it and returned it, and asked Raúl what he did. Raúl said he worked in artificial intelligence, building algorithms for HR software. The friend connected them over Skype, and Raúl explained what AI could one day do for Éric's mission.

Afterward, Éric emailed his friends under the title "God was in the dog." He predicted that people would one day ask Bible questions on their phones and get instant answers drawn from the words of Jesus, essentially describing retrieval-augmented generation (RAG). He guessed it would take ten years. It took about thirteen.

Raúl attended Missional AI 2025, where Éric finally asked the dog's name: Hadassah, the Hebrew name of Esther, whose story gives us the phrase "for such a time as this."

Six days to a prototype: building Hello Bible

When generative AI arrived, Éric built a working prototype in six days and grew it into Hello Bible through a year of testing.

The idea was older than the dog story. Twenty years ago Éric had sketched a Bible chatbot called VIP, "Virtual Intelligent Paul." While skiing in the French Alps with his wife, Muriel, he suddenly realized that generative AI made it possible. Back home, he prayed: "Lord, you made the world in six days. Help me make my prototype in six days." He did, and thousands of people soon began asking it biblical questions.

An MVP followed, built with engineers in Madagascar. After a year and hundreds of thousands of conversations, learning prompt engineering and how to use RAG for memory, the project moved to a team in France and became Hello Bible. The name is a nod to the "hello" that greeted the world when Steve Jobs launched the Macintosh.

Éric's vision is to bring the Bible to each person according to their context, language, background and story. A recent testimony from a man named Tim described Hello Bible as a beacon in his darkest moment, giving him the interaction and support his previous Bible app lacked.

Why the church needs an open-source Christian LLM

General-purpose models aren't aligned with a Christian worldview, so Éric is fine-tuning an open-source model the whole church can use.

Éric compares ChatGPT to a great general practitioner, not a specialist. He once asked it why Matthew has fins in The Chosen. Instead of pushing back on the absurd premise, it invented a reason, then apologized and invented another. Good prompting helps, and Hello Bible still uses commercial models with careful prompts, but Éric concluded it isn't enough.

He also points to values. In his own testing, he says, a model readily joked about Jesus but declined to joke about Muhammad. Models like ChatGPT, Gemma, Llama and DeepSeek, he argues, are aligned to value systems that aren't necessarily Christian.

So at Missional AI 2024 he called for a Christian LLM, and partners including Scott Beck of Gloo said, "Let's do it." Over the following year, the work has involved:

• Fine-tuning, not building from scratch. Theologians from Protestant, evangelical and Catholic traditions defined the essential content for training.
• An evaluation tool. It checks that the model gives better answers without any prompting.
• Rigorous testing. Blind tests with theologians plus G-Eval, which uses one AI to assess another.

Once it proves better, the model will be released open source for Christian organizations. "It's not my kingdom. It's not my app. It's not my AI," Éric says. "It's God's kingdom."

Ministry from a post-Christian context

Growing up in secular France taught Éric that the entry point for the gospel differs everywhere, and that AI can help meet people where they are.

In the US, he notes, talking about God is normal, churches are everywhere and Christian books sit in airport shops. France is different: largely secular, with Christianity there mostly Catholic and often met with opposition. Like the apostle Paul, he says, we must become Greek to the Greeks, and French to the French. Without understanding someone's context, we can't help them understand the Bible.

AI as the next chapter of Bible access

Éric sees AI as the next step in a long line of tools that opened up Scripture: Gutenberg's press, Bible Gateway's website, YouVersion's app, and now AI.

The need is real. His church near Paris, MLK Church, baptized 700 young people in a single year, yet Éric believes most of them don't read the Bible. He estimates that fewer than 5% of Christians in the Western world engage with Scripture daily. Even YouVersion, with hundreds of millions of downloads, shows how wide that gap is.

His goal is not to impose his own interpretation but to put the Bible in front of people and let the Holy Spirit make it alive. He shares the story of a national president he advises, who opened the Bible at 3 a.m. and read God's words about seeing His people's suffering under Pharaoh. The president immediately knew who the "Pharaoh" in his own country was.

In its first months in France, Hello Bible has seen a 25% engagement rate. Éric's hope is a Bible assistant in every pocket, helping people connect with God, His Word, prayer and each other, not isolating them.

Watch Éric's mainstage keynote from Missional AI 2025

Éric took the case for a Christian LLM to the main stage at Missional AI 2025 in his keynote, "Building a Christian LLM: Aligning AI with Biblical Values." You can find it in the Missional AI Video Library under Dallas 2025 Keynotes.

In this interview he previews the argument he made on stage: that today's leading models carry value systems that aren't necessarily Christian, and that the church needs an open, aligned alternative. The keynote goes deeper into why, and how his team is building and testing it. Watch it alongside this episode for the full picture.

Listen and join the conversation

Listen to the full episode with Éric Célérier on the Missional AI Podcast, and subscribe so you don't miss future conversations.

Éric will also join us at Missional AI London on July 17, a one-day gathering of leaders from across the UK, Europe and the Middle East exploring faith and AI. Find out more and register at missional.ai.

This episode was made possible in partnership with Gloo, the technology platform connecting the faith ecosystem.

Sources

• Missional AI Video Library