Sinner Saint: A Surprising Primer to the Christian Life

by Michael Horton

Few mysteries of the faith are so perplexing as the ongoing presence of sin in the life of the believer. On the one hand, Christians are no longer slaves to sin. On the other hand we find ourselves rocked by it, daily battling conflicting impulses and neuroses, caught in the middle of a cosmic tug-of-war between good and evil desires. What are we to make of this? Whatever we may believe theologically, practically speaking, the struggle is universal. The honest truth is that we're not as good as we would like to be. In other words, the answer to the question "Could I be better?" is always a resounding yes. Various answers to this problem have been posited throughout the history of the Insufficient faith. Lack of willpower. Incomplete sanctification. All such answers, however, envision a kind of progress where we shed our old "sinner" and experience a kind of metamorphosis into the new "saint." But does such an explanation actually jive with what we experience? Does such an operative principle play out consistently in the lives of the great heroes of the faith? And, most importantly, does it actually align with the full counsel of God? What if there were another option, a way of understanding ourselves that shunned simplistic "either-or" explanations for a more honest "both-and"? What if there were a way of being real about our failures yet insisting that, in Christ, they don't define us? Welcome to the reformation doctrine of the simul, where we find ourselves sinful and righteous, broken and redeemed, and–above all–unconditionally loved by the God who overlooks our shortcomings on account of his Son.

Genres: Nonfiction, Theology

160 pages, Paperback

Published May 13, 2025

Reviews

[Alex Steele · Rating 4 out of 5]

This book deeply ministered to my heart. As someone who wrestles daily with sin, I often wonder, “If I’m a new creation in Christ, why do I still struggle so much?” Kjolhaug offers gospel clarity: the Christian life on this side glory is lived in the tension of being both sinner and saint. This simul paradigm “… frees us from soft-pedaling sin by maintaining the depths of our depravity and the strength of our Savior” (144).

Rather than striving to “grow up” into independence, we’re called to “grow down”—to become more deeply rooted in Christ, our source of life. This is the essence and everyday rhythm of the Christian life.

[James Rickenbaker · Rating 5 out of 5]

What a masterpiece! In this book, Pastor Luke Kjolhaug does an excellent job walking his readers through the simul (we are at once both sinner and saint). He writes in a very readable and relatable way about the struggles in life that we have.

Ultimately, this book is about the doctrine of sanctification. Pastor Kjolhaug gets it right. Sanctification is not about getting better everyday. It’s not about growing upward, but growing downward. Sanctification is falling more and more into the loving arms of Jesus everyday. Sanctification is found in the constant struggle with the old Adam, yes. But sanctification is not measured in committing fewer sins, but in the deeper recognition that we need Jesus every moment of every day.

This is truly one of the best books I have ever read. And it’s certainly the best book I have read on the subject of sanctification. I can’t recommend it highly enough.

[Lianna Davis · Rating 3 out of 5]

The reminders I took away from this book are that I remain someone with flesh, as the Apostle Paul put it—someone who still sins and must contend with remaining sin. I appreciated the book’s emphasis on the Spirit and on “growing down” in dependence upon the true Vine, the Lord Himself, for sanctification.

At the same time, I hold a more optimistic view of how much change the Spirit can bring to a person’s life. There are sins that I am truly not tempted by in the same manner or to the same degree as several years ago. That is the Spirit’s power at work in me—and God using suffering for my good.

This somewhat mixed perspective is why I settled on three stars. Yet the reminders mentioned first deserve a higher rating, because I am thankful for this book. It helped me recognize that I cannot strive to be more than I will be on this earth: a sinner-saint.

[Andrew Gates · Rating 5 out of 5]

Why do believers still struggle with sin? And how are we to make sense of this reality, especially when we are told that believers have been set free from the power of sin and should be ever-increasingly holy? ... These are the questions this book seeks to answer and does so by appealing to the classic Reformation of the simul - simul justus et peccator (simultaneously justified and a sinner). This book is superb and reveals the great personal and pastoral need to recover this essential but neglected doctrine. I commend this book wholeheartedly.

[Elise · Rating 5 out of 5]

There's a simplicity to this book. Kjolhaug briefly and deftly takes us poor sinners through an overview of several doctrines that are at the heart of what we believe. Once saved, are we now saints (we are!) or are we still sinners? (We are!). What does it mean to be justified and how does sanctification work? If I'm truly a Christian, why am I still struggling with sin?

This book is a primer—so it may feel basic at times. I still found it encouraging and could envision reading it with a new Christian as they wrestle with these new ideas.

[Lucas · Rating 5 out of 5]

Easily one of the best books I’ve read this year.

Luke wires with great clarity and wit as he highlights the “simul” - we are 100% sinner, 100% saint - and reveals how our sanctification grows downward as we become more rooted in Christ and dependent on Him.

[Elisabeth Dill · Rating 5 out of 5]

A very encouraging/comforting read. Every Christian ought to read it.

[Timothy Koch · Rating 5 out of 5]

This book is a true "primer" on the doctrine of 'simul justus et peccator.' It is accessible and clear and well-written. I was particularly impressed with this book's eye toward pastoral-care. The 10th chapter is the best chapter of the entire book...but the nine chapters leading up to it are pretty good, too.

I'm grateful for this book, and would heartily recommend it to anyone who is distressed/burdened by the lack of visible progress in their morality as a Christian.

[David L Fendt · Rating 5 out of 5]

Excellent book

[Gavin Stahl · Rating 5 out of 5]

a must read for understanding how we (as believers) can be simultaneously sinners + saints!