Organisers hope Frenzy 2006 will attract at least 9000 music fans to the city on June 10 - double the number who attended last year's inaugural event.
Topping the bill will be Delirious?, a band which has already had a string of top 20 UK hits and established a strong following, even outside Christian circles.
American singer Kendall Payne, who featured on the soundtrack of Hollywood film Never Been Kissed, and South African group Tree63 have also been lined up for the extravaganza.
Frenzy is run by Lemonade Productions, a company launched by six friends from Dunfermline's expanding evangelical Vine Church, housed in a former lemonade factory, which was recently at the centre of a dispute after neighbours complained about loud music from its sermons.
Justin Dowds, managing director of Lemonade Productions, said the Highland Hall event was also open to non-Christians.
He said: "There is not an event in the UK like it - a whole day dedicated to Christian rock music.
"After last year's event we did lots of surveys to gauge how many people we were likely to attract this time and we expect it to be 9000, or maybe even more.
"It's geared towards families as we do not sell alcohol and people can enjoy a picnic outside.
"We have bookings from all over England and Scotland and have 50 coming from Poland. We're hoping that there's going to be another 50 coming from Sweden too, as well as people from other European countries such as France and Italy."
He added: "At the Vine Church, we have found a way of communicating the Gospel effectively with young people and use a band with electric guitars, and we attract around 400 to 500 people on a Sunday morning, with more people coming along to groups during the week.
"Our music is more similar to U2 than traditional hymns and we use the words in a way that people understand."
City culture and tourism chiefs today welcomed news that the festival's popularity was set to snowball.
Councillor Ricky Henderson, executive member for sport, culture and leisure, said: "We hope all those planning to come to Edinburgh in June for the music festival will enjoy their visit.
"Significant one-off festivals such as this contribute greatly to the economy and the cultural vibrancy of our city."
He added: "Hopefully, those who come will be attracted back to Edinburgh in future and I'd be very happy if the festival became an annual event."
A VisitScotland spokesman said: "This is great news for Edinburgh and the surrounding area. Festivals are an integral part of attracting visitors to Scotland and we certainly welcome anything that will support tourism and illustrates what the country has to offer.
"Cultural activities such as this are key to VisitScotland's promotion of the country as we strive to build tourism spend by 50 per cent by 2015."