The following is an excerpt from Thaddeus Williams’ new book (Zondervan Reflect), a systematic theology text on the divine attributes in the tradition of Packer’s Knowing God, Colson’s Loving God and Piper’s Desiring God, complete with personal and small group study guides, along with personal testimonies from leading theologians — including Fred Sanders, Michael Horton, Erik Thoennes, John Perkins and Joni Eareckson-Tada — on how specific divine attributes have impacted their personal lives.

Every time I enter a lecture hall at Biola University, I commence the class with the same two words: “Greetings, theologians!” In the chairs sit art, film, communications, psychology, business, art, science and Bible majors, among others. Yet I greet all of them as theologians. It’s not a gimmick. I want every student who comes through my classroom to walk out with a sense that, as R. C. Sproul loved to say, “everyone is a theologian.”

But what else goes into this sacred task of theology? Five hundred years ago, Martin Luther famously listed six requirements. In one of his famous Table Talks (number 3425, to be exact), the stout German Reformer highlighted:

1. The grace of the Spirit.

2. Anfechtung, a German term for terrible dread or agonizing struggle as we realize our utter helplessness without God.[1]

3. Experience — not just abstract pondering but real-life, transformative personal encounters with God in his Word and in a local flesh-and-blood community of fellow believers.

4. Opportunity — spotting and taking daily moments to share gospel truths with others.

5. Consistent reading and study of sacred Scripture.

6. Broad engagement with other academic disciplines.

Two hundred years ago, former slave and the first black theologian ordained as a minister in the United States, offered five marks of a theologian:[2]

1. L