The once vibrant Christian South is beginning to become a "boneyard of religious history", warns one US pastor.

There may be a church on every street corner but many of them are dying, if not dead already, said Tyler Jones, lead pastor at Vintage21 Church, in Raleigh, North Carolina.

Jones has joined several pastors this week to sound the alarm on the decline of the church in the South – a decline that he believes is happening faster than anywhere in the country.

And the decline, they say, isn't due to the external changes in the South, such as urbanisation and intellectual and cultural growth. Rather, the problems are within the church.

In the South, the people are not unreached but wrongly reached, Jones said at "Advance10: Contextualising the Gospel in the New South", a three-day conference that kicked off on Monday.

Churches have failed to understand the Gospel and how it applies to people's lives in a rapidly changing culture, he noted. Christian faith in the South exists primarily in name alone, he stated.

Though a majority of residents in the South claim to be Christian, many are being taught "quaint moralism over the Gospel", the Raleigh pastor lamented.

And "moralism is the greatest form of self worship", he warned. "It robs us of our need for God."

Jerome Gay, lead pastor of Vision International Church in Raleigh, also views moralism as a pervasive problem in the churches.

"Too long within the South, Christianity has been presented as a list of don'ts. Don't go to the club, don't join the frat, don't do this, don't do that," he pointed out.

The result is an increase in the "culture of the dechurched – people that have been burned by church, experienced a ton of church hurt".

"And they don't actually know Christ because they haven't been presented with the God of the Bible. They've been presented with a list of do's and don'ts."

The conference is being put on by a cooperative movement called Advance the Church, which seeks to "assist local churches in planting healthy, Gospel-centred churches and revive the boneyard of dead or dying churches – beginning in the context of the urban south".

Pastors in the South recognise the need for churches to get serious about their mission, respond to the changing culture without watering down the Gospel, and radically reorient their very existence to not only reach the unreached but also those who grew up in the pews.

David Platt, pastor of The Church at Brook Hills in Birmingham, Alabama, said there was a definite question among many churches as to what the Gospel was and that there was a great need for clarity on the Gospel.

"I think there's a real comfortability level that the Gospel is almost assumed when the reality is a lot of people who [grew] up in the church need to hear the Gospel truly as it's presented biblically and need to be saved and are being saved," said Platt.

According to missiologist Ed Stetzer, the biggest challenge in the churches is that they have made it acceptable for people to do nothing and call themselves Christ followers. He contended that sitting next to someone on Sunday did not guarantee biblical community.