A cutting-edge church leader in the US known for his innovative ideas on reaching a post-modern generation for Christ contends that the reason why churches are declining in America is because they are self-centered.

"My primary assessment would be because American Christians tend to be incredibly self-indulgent so they see the church as a place there for them to meet their needs and to express faith in a way that is meaningful for them," said cultural architect Erwin McManus, lead pastor at Mosaic Church in Los Angeles, to The Christian Post on Monday.

"There is almost no genuine compassion or urgency about serving and reaching people who don't know Christ," he added.

McManus, whose church members' average age is 25 years old, is known for breaking the "rules" of traditional church and applying spiritual creativity to engage and develop the next generation of Christian leaders.

Since becoming lead pastor of Mosaic about a decade ago, McManus' church membership has grown from about 300 adults to more than 3,000 adults. The historically Southern Baptist church also boasts over 40 different nationalities and is "packed" with artists such as musicians, writers and filmmakers.

Among the attendees are also 80-year-old members from the generation before McManus arrived, who are said to "root on" the younger generation of church members.

While Mosaic and more modern churches are growing, many mainline Protestant churches are reporting worrisome decline in membership.

The United Methodist Church reported last year that its membership was at its lowest since 1930 with just over eight million members.

Meanwhile, the Lutheran World Federation reported that although its global membership increased in 2006, its western membership declined. Lutheran Christians in North America in general decreased about 1.41 per cent, while the LWF witnessed a 1.73 per cent drop.

The second largest LWF member church, the Evangelical Lutheran Church in America - accounting for 4.85 million members - saw about a 1.6 percent drop in the same year.

Speaking about church decline in general, McManus concluded: "I think the bottom line really is our own spiritual narcissism. There are methods and you can talk about style, structure and music, but in the end it really comes down to your heart and what you care about," he said.

He often explains that while the Bible does not change, the methods to effectively communicate the Word of God can.

The self-described cultural architect, someone who leads by combining both creativity and organised systems, helped put together this week's Rethink Conference at another California megachurch, Crystal Cathedral. The conference will converge global leaders such as Rupert Murdoch, Larry King, former President George HW Bush and Christian thinkers to help pastors and ministry leaders better understand the world and thus improve their ability to communicate the gospel.

McManus and Mosaic Church will also host the annual Awaken conference from April 1 to 3, where prominent innovative Christian thinkers will offer different perspectives on developing ministry and the church.

Some of the Awaken speakers include Bill Hybels of Willow Creek Community Church; Lee Strobel, bestselling author of The Case for Christ; Mark Batterson of National Community Church; and Hollywood producer Ralph Winter.