The Church must embrace every technological tool at its disposal to engage with today's digital world or else lose the next generation, the head of the Lausanne Movement has said.

Dr Michael Oh laid out the vision for the global evangelical movement during its 50th anniversary celebrations in Incheon, near Seoul in South Korea, on Tuesday night.

The celebration was held during the Fourth Lausanne Congress on World Evangelization that has brought together over 5,000 Christians from over 200 countries, with thousands more joining virtually.

Dr Oh said during Tuesday night's celebration that the Church needed to be strategic and intentional in reaching and discipling young people growing up in a digital world.

Identifying three priorities for the next phase of the Lausanne Movement's work, he called for a commitment to disciple-making in the world, "disciple-maturing" in the Church, and increased digital engagement.

Towards this aim, the movement is currently developing a set of digital tools to help Lausanne members collaborate and engage digitally.

Dr Oh urged them to use the tools as he warned against regarding digital engagement as "a side or specialty ministry" at a time when many young people's everyday lives are digital.

"We recognise that the world in which we are living is increasingly a digital world and the best tools to unite us in disciple-making and disciple-maturing are digital," he said.

"It would be to our great detriment and grave danger to ignore digital - either to ignore it foolishly, or embrace it naively.

"Regardless of how we feel about it, it is shaping our young people and shaping our world - one billion Tik Tok users, 8.5 billion Google searches every day.

"Digital is shaping what people want, what people know, and what they do. We know that the Gospel is powerful enough to save and shape lives ... but young people are hopelessly inaccessible and lost if we do not enter their digital world and engage them with digital tools.

"We need strategic intentionality to reach and disciple the younger generations or we will lose the future."

It is 50 years since the late American evangelist Billy Graham convened the 1974 International Congress on World Evangelization in the Swiss city of Lausanne. That conference effectively launched the global Lausanne Movement with a vision to accelerate global missions.

Elsewhere in his keynote address, Dr Oh said that Christians should not be resigned to lamenting the state of the world, but proactively seek to change it. However, he warned that the time to act was now.

"Ultimately this week is not about 2024. It's about the world in 2050 - the world of our kids and grandkids," he said.

He continued, "Shaping the world in 2050 can't start in 2045. It has to start now and we have a once in a lifetime opportunity to do this now - together.

"That is the power of movement and collaboration, and that is the future we are committed to shape as the Lausanne Movement."

During the evening, greetings were shared by Will Graham, the grandson of Billy Graham, who shared his belief that his grandfather and fellow conveners of the 1974 conference would love nothing more than to see everyone at the congress go out into the world to spread the Gospel. He urged delegates not to give up despite the challenging global context.

"Exactly 50 years later, the task is still unfinished. The necessity of proclamation evangelism is as great today as ever," he said.

"Even though we're living in a world that at every turn is working to cancel Christ and the Bible in order to exalt itself, my friends, we must say: not on our watch.

"Now is not the time to stand down, it's not the time to give up, it's not the time to retreat. It's not a time to turn inward. Now is a time to take spiritual ground. Now is the time to stand boldly for Jesus Christ and preach Christ unashamedly in the spiritual power of the Holy Spirit."