IRVING, Texas -- On the 25th floor of a luxury office tower in Irving, a church most people have never heard of is planning to save America. Its leaders believe Jesus has sent them to spread a difficult truth in the United States - that demonic forces are corrupting society and only spiritual warfare can stop them.

Call it the message. The messenger comes from Nigeria.

The Redeemed Christian Church of God was founded in Lagos by men and women who were once the target of missionary work themselves.

Now, their church is one of the most aggressive evangelizers to emerge from the recent advance of Christianity across Africa. Their offices in suburban Dallas' high-tech corridor reflect the group's bold, entrepreneurial approach.

The Redeemed Church is part of a boom in African churches establishing American outposts. It's opened more than 200 parishes in just over a decade, from Chicago and Atlanta to Washington and New York. It's training Americans of all races to help them reach beyond the African immigrant community.

Fifty miles north of Dallas, the church is building a multimillion-dollar national headquarters and conference complex on more than 600 acres of farm land in rural Floyd, Texas. The site is modeled on the denomination's massive campground outside Lagos and is expected to draw thousands of followers for marathon prayer meetings that are the hallmark of its worship style.

At the center of their North American push is a for-profit, satellite TV network, launched in December from Dallas under the name Dove Media. It broadcasts sermons from the church's world leader Pastor Enoch Adeboye between reruns of “The Dick Van Dyke Show'' and “Bonanza.''

Dove hopes to attract viewers throughout the continent who would not normally watch Christian TV.

A look at the beliefs and worship styles of African Christians

Are they uniquely African, traditional Christian or both? This is what religion experts are asking about the teachings of the nondenominational churches from Africa, where Christianity became a major force over the last century.

The churches cover a wide spectrum of belief and worship, but many are either Pentecostal-charismatic or are heavily influenced by that Christian movement.

Pentecostalism began in the United States 100 years ago and embraces spirit-filled worship, miracles, speaking in tongues and spiritual healing. Its followers are biblical conservatives, who see the devil behind calamities both global, such as war, and personal, such as childlessness.

But some African Christians still cling to indigenous traditions. Witchcraft is an example. African Christians do not practice witchcraft, but some see it as another manifestation of the devil, something that can be fought through intensive prayer.

A smaller number also continue to venerate their ancestors in addition to believing in Jesus Christ.

The Redeemed Christian Church of God emphasizes it is wholly Christian, not some mix of African and Christian beliefs.

Still, Americans and Europeans may be alienated by its leader's annual prophecies from God, which are vague but touch on international issues as well as spiritual life.

The Nigerian church also may draw objections over its linking of the Bible and personal success. Redeemed Church pastors insist they do not promote “Prosperity Gospel,'' which teaches that donating to the church and living like a true Christian will bring wealth and other earthly rewards.

However, the Nigerian church heavily emphasizes God's desire for personal achievement.

Philip Jenkins, author of the book “The Next Christendom: The Coming of Global Christianity,'' cautions against dismissing African Christianity as outside the bounds of the faith. He said most of the differences between Western and African Christians are cultural not theological, and derive from different ways of reading the Bible.