Influential theologian J I Packer wants evangelical churches to recover catechesis, or systematic instruction in the essentials of the Christian faith.

Packer believes the idea is an alien concept to most evangelicals.

"We are drifting back into paganism, that’s the truth," he said in a lecture last Saturday at St Matthew’s Cathedral in Dallas, according to The Living Church News Service.

The 83-year-old Anglican priest has co-authored a new book, Grounded in the Gospel: Building Believers the Old-Fashioned Way, in which he makes the case that catechesis is a non-negotiable practice of churches and is of no less value than Bible study and expository preaching.

During Saturday's lecture, he said he yearns for "Bible-based, Christ-centred, declarative in style". But recovering catechesis in churches will be a challenge, he added. Earlier, he called it the greatest challenge for the 21st century church.

It's "ridiculous to think that no more learning of the faith is necessary after confirmation has taken place," the renowned theologian noted, as reported by The Living Church News Service.

"Ongoing learning is part of the calling of the church. It has to be taught in all churches at all times."

In 2008, Packer and 10 other clergy left the Anglican Church of Canada over its liberal direction on scriptural authority and homosexuality. He joined the more conservative and orthodox Province of the Southern Cone in South America.

Packer was named one of the 25 most influential evangelicals in the world by Time magazine in 2005.