Welcome to In-Depth Studies!

IDS is a teaching ministry of Geoff Volker. Our purpose is to stimulate your thinking on significant Biblical issues. Our theological point of view is that of the Reformation in that we hold to the Doctrines of Grace (TULIP). We differ from Reformation theology in areas such as infant baptism and the Sabbath. We also teach from the perspective of New Covenant Theology. Take your time and browse our site – we hope we can be a useful resource for you!

April 29 Colloquy “Is the Cross Alone Sufficient for Salvation?”

Join us 6:30-9PM Saturday, April 29 at Gilbert Regional Library and experience a colloquy addressing the question, “Is the Cross alone sufficient for salvation? Dr. Brian Arnold will take the NO position and Geoff Volker will take the YES position. Refreshments will be provided; no child care.

  • Dr. Arnold joined the Phoenix Seminary faculty in 2015 and teaches courses in Systematic Theology and Church History. He has prior teaching experience as a Garrett Fellow at SBTS, where he served as a Lecturer in areas such as: Church Leadership, New Testament (Greek), Old Testament (Hebrew), Church History and Theology.
  • Geoff Volker is the Director at In-Depth Studies and an Elder at New Covenant Bible Fellowship.

Free Admission (love gift offering will be taken).
For more information, contact:

  • Geoff Volker at Volker.geoff@gmail.com. 480-313-8558
  • Paul Honeycutt at Honeycutt.paul@gmail.com 480-206-6978

The pages of our site are loaded with theological articles on a wide range of topics explaining our views. Be sure to visit the Reading Room while you’re here and feel free to download anything of interest to you. Don’t forget to visit Theological Inquiry as well. Theological Inquiry is the section of our site that provides you the opportunity to interact with us in asking any theological question that you’re facing.


New Book

Picture-Fulfillment: A Study in New Covenant Theology

“Excerpt 2 | What is a Covenant?


What is a Covenant?

There is no debate that the concept of the covenant is a significant idea in Scripture (1 Corinthians 11:25, Hebrews 8, Galatians 4:21-31). But there is much debate concerning what is a covenant and how we are able to identify a covenant.

Let’s first tackle the question as to exactly what is a covenant? I would say that a covenant is some sort of an arrangement between two parties. In saying what I have said I am very aware that my definition is a bit vague, but it is vague by design. In Scripture there are a variety of types of covenants. We will examine each covenant…” Read more


Learn About New Covenant Theology

Want to systematically learn about New Covenant Theology? Listen to our 26-session audio course to get started!

Current IDS Newsletter

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The In-Depth Studies Blog

A way to keep up with the latest theological ramblings of the IDS blog team. You’ll have the opportunity to interact with the IDS bloggers on a wide variety of subjects.

In-Depth Studies Audio

A clearinghouse for In-Depth Studies audio files from a variety of IDS speakers.

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Critics Choice Vacations

Planning a personal trip or family vacation? Enjoy your destination hassle-free with Critics Choice Vacations, the official travel agents for In-Depth Studies. Susan and Curtis Boehnstedt are good friends and believers, so we heartily recommend their service to you. Get started today by visiting their website: http://criticschoicevacations.com/