"What role are you being called to play in the battle for your friends' souls?" asks an e-mail the organisation sent to 50,000 young people about how to share their faith using Halo 3.
Studies have shown the negative influence of media, including video games, on young people. A recent US Barna Group poll revealed that children will have seen countless murders among the more than 30,000 acts of violence that they are exposed to through television, movies and video games.
But youth workers say churches need to be up-to-date on the latest cultural trends especially something that young people are inevitably going to participate in.
"Video games are a living and breathing part of our culture and will only continue to grow," said Tim Schmoyer, a pastor of a student ministry in the US. "We need to be aware of the messages and values kids are unconsciously swallowing and teach them to consciously filter it all through Scripture."
An Ellison Research study found that churchgoers and pastors are not very familiar with video and computer games. Half of lay people are not informed and more than 70 percent of clergy are disengaged from that area of culture.
"Pastors need to be informed about what's out there in order to understand how the culture is influencing the people they are trying to reach," said Ellison Research President Ron Sellers.
But how relevant is too relevant especially when it involves killing?
Halo 3, for example, is rated "M" for mature audiences.
"To justify whatever killing is involved by saying that it's just pixels involved is an illusion," said Daniel R. Heimbach, a professor of Christian ethics at Southeastern Baptist Theological Seminary, according to The New York Times.
Still, Christian gamers online say "it's a way to fellowship."
And others call it a fishing hook.
"Teens are our fish," Gregg Barbour, youth minister of Colorado Community Church in the Englewood area of Denver, told the Times. "So we've become creative in baiting our hooks."
Since the Sept. 25 launch of Halo 3, more than 2.7 million people have logged on to Microsoft's online service, Xbox Live, to collectively play 40 million hours of "Halo 3" with other gamers, Microsoft reported.
In the game's first 24 hours on sale in the United States, sales hit $170 million, the company added.
