Gregg Allison, a professor of Christian theology at the Southern Baptist Theological Seminary in Louisville, Ken., describes himself as an “eclectic theologian.” He’s authored, coauthored, or edited 16 books. And while each tackles a unique subject, they share a throughline. “I’m particularly interested in topics that are overlooked or underdeveloped,” Allison tells PW.

In his forthcoming book, Complementarity: Dignity, Difference, and Interdependence (B&H Academic, May 2025), Allison draws upon ancient philosophy, theological developments, modern feminist movements, the Old Testament, and the New Testament to examine two Evangelical takes on gender: egalitarianism and complementarianism. Both draw beliefs from scripture but are opposed in their views of men and women; egalitarianism holds that men and women are equal in essence, relationships, and roles, while complementarianism posits an equality of essence but different roles in the church and the home.

Instead of supporting or refuting either position, Allison offers a novel one: “complementarity.” Allison defines this as “God’s design for men and women as male and female image bearers to fill out and mutually support one another in all areas of their lives.” It is meant to be “a call for mutual respect, harmony, and reciprocity,” that he hopes will be a foundation for both movements.

Allison coined the term during a Harbor Network church planting strategy session in 2021. “We were trying to hammer out the ministries of men and women in the church and find some common ground,” he says. “I searched the terms ‘complement’ and ‘complementary’ and pieced together a definition from that.” Audrey Greeson, a former B&H Academic acquisitions editor who was at the session, later reached out to Allison to write a book on the subject.

Some may view Complementarity as radical, but Allison says that’s not his intention. “If you miss the big idea of what I’m trying to do—provide a foundation for both complementarianism and egalitarianism and show that which unites us—then I can see how there will be criticism,” he says. Michael McEwen, a B&H Academic editor who began working with Allison on this title in late 2022, explains further: “It’s not throwing grenades toward one another, but rather about having thoughtful, articulate discussion rooted within scripture and theology.”

Readers may look for Allison’s notions of gender roles, but they’re not a subject he tackles in Complementarity. “Roles, responsibilities, functions, and ministries are secondary matters,” he says. Furthermore, he says, “there are so many landmines when it comes to discussing gender roles. I’ve turned down an opportunity to delve into them.”

“
There are so many landmines when it comes to discussing gender roles.
”

McEwen agrees that conversations around gender roles and functions are particularly difficult. That’s one of the reasons he sees Complementarity as a “timely message for the broader Evangelical readership.” McEwen believes Allison’s “charitable and humble tone will have people gravitating toward this message at time in which we need it.”

Zoë Ettinger is a writer and editor living in Brooklyn.