Some radicals are unbalanced. Others help us regain our balance.

Howard Snyder—whose prior books include The Problem of Wineskins (1975) and the Radical Wesley (1980)—helps us maintain theological equilibrium by constantly testing the state of the church against the teaching of the Bible. He sounds radical because he thinks that somehow, in the power of the Spirit, we can live out that teaching.

Snyder's latest book, Decoding the Church (Baker, 208 pages, $14.99), elaborates the familiar biblical metaphor of the church as a body using contemporary concepts: DNA and ecological systems.

When the apostle Paul writes about the church as a body, his main messages are diversity of gifts and interdependence of members. He secondarily draws out the related notions of unity, growth and maturation, and reconciliation.

In Paul's thought the body is not a simile for the church. The church is not merely like a body. The church does not merely resemble a body in its diversity, unity, and interdependence. It is the body of Christ, who is its head. Every member of the body is, in a mystical sense, a part of Christ.

For 50 years, we have known scientifically what Paul presumably didn't (though it extends his thought nicely). We know that every cell in the body shares the same genetic code. The DNA in the head is the same as the DNA in the toes and the elbows.

Snyder wants to join the DNA metaphor to Paul's body metaphor as a way of saying that the reality of the church's relation to Christ is deeper and more complex than we might think.

DNA is, as Watson and Crick announced in 1953, a double helix. Snyder asks whether our churches have been operating with only half their DNA. He takes the creed's four classic marks of the church (one, holy, universal, ...