How does Scripture hold the Church in one faith?

Four voices. One question.

How does the Christian know what is true?

Trusted voices across the Church’s traditions — kinship and honest difference. Not four jackets alone, and not a curriculum you must buy as a set.

Editions prepared for deep reading — so you can stay with the question.

Available now · Official publication August 15, 2026

Kinship and honest difference

When division and heresy make the ground feel thin, the Church has not been silent. These four editions gather teachers who have answered the same question from different places in the tradition — Patristic West, Protestant, Catholic, and Orthodox. They do not secretly agree on everything. That is the point: kinship without flattening difference.

Four voices on that question

Oldest to newest. Each Member Edition stands alone for deep reading — open any title. A group starts with one voice; the others wait as invitation.

How a group starts on this question

One voice first — about six to eight weeks. You can buy today. You do not need the other three titles to begin, or to finish well. We recommend starting with Tertullian’s short classic on the Rule of Faith.

Recommended start: Tertullian

Free eight-week discussion guide for reading groups — protects group pace for deep reading together — then one pack for your people.

Download the Tertullian guide

Pack of 8 (recommended): hardcover $280.80 · ebook $136.80

You buy as the facilitator. Hardcovers ship to you; share them when you gather. Share unlock links so each member gets their ebook and 90 days of study — unlocks are not extra hardcovers. Packs and the guide protect group pace — one voice, weeks of deep reading together. Members use the edition and Ignaria to keep asking the text with citations — not an AI sermon.

Hardcover pack of 8 — $280.80 Ebook pack of 8 — $136.80

Tertullian title page

Also packs of 4 and 6 on the title page.

Also on this question

Prefer another voice for your group — or continue after Tertullian? Each edition has its own free guide and packs. Continuation is invitation, not a requirement.

Editions and study

Hardcover $39 · Ebook $19

Own the classic. Study with the Church across the centuries.

  • Hardcover includes instant ebook downloads (EPUB, AZW3, PDF)
  • Prepared editions with apparatus and free reading-group guides — not a raw archive dump
  • Each new title unlocks 90 days of Ignaria Pro — study after the book
  • Trusted voices guide — you interpret; never an AI pastor

Reading alone? Buy any single on its title page. Leading a group? Use the recommended start above — or shop every edition in the catalog.

View catalog Tertullian for yourself