Jonathan Edwards’s Religious Affections is a tremendous book. It’s potentially a devastating book. The question it addresses — what are the distinguishing marks of one who is in favor with God? — is an unavoidable one for a follower of Christ. How do I know that my faith is genuine? How do I know that I’m a real Christian, and not a hypocrite?

The possibility that my faith is false, and the fact that this book might help to reveal the falsity, is why it is potentially devastating. But this sort of devastation is good. If my faith is misguided or lacking or deficient or false in some fundamental way, far better that I discover it now than that I arrive at the final judgment only to hear Jesus say, “I never knew you; depart from me” (Matthew 7:23). Far better for Edwards to devastate me with his writings than for Christ to devastate me with his dismissal. Recovery from the former is possible; repentance is still an option. But there is no recovery from the latter. “It is appointed for man to die once, and after that comes judgment” (Hebrews 9:27).

But the book is potentially devastating for another reason. It’s a complicated book, a meticulous book, a book by a veritable genius, written in the style of an eighteenth-century pastor and theologian. It’s the fruit of decades of theological reflection on revival, religious experience, the challenge of assurance, and the difficulty of discerning the work of God on earth. It was written on the heels of the First Great Awakening, the fourth book on the subject by its author, and his most mature reflections on the challenges posed by the revivals that swept Europe and America in the middle of the eighteenth century. The complexity of the subject and the precision of the author’s prose mean that this book can be misunderstood. And in misunderstanding, we can be devastated. Our faith might be wrecked, not because it is false, but because it is real, and we wrongly apply Edwards’s signs to ourselves.

In commending this book to the reader, I’m mindful of both types of devastation. I want to foster the first kind, if needed, and avoid the second kind, if possible. To that end, I offer a ten-step orientation to the book as a whole. Think of these as ten items to keep in mind as you embark on the difficult but valuable journey before you.

1. Structure

The book has three parts. Part 1 introduces the thesis — true religion, in great part, consists in holy affections — and then proceeds to define what is meant by affections. Part 2 then identifies twelve unreliable signs of holy affections, and then part 3 identifies twelve reliable signs of holy affections (this is the meat of the book). Definitions. Unreliable Signs. Reliable Signs. That’s the basic structure.

2. Meaning of Affections

Understanding what Edwards means by affections requires understanding a bit about his view of humanity. As a human being, you are made up of a body and a soul. Your body has five senses, by which you take in impressions from the external world. Your soul, or your mind, has two fundamental faculties or powers. The first is the understanding. It’s the faculty by which you perceive, discern, view, and judge. It tells you what something is. The second faculty is the will, by which you like or dislike, love or hate, approve or reject what you perceive with your understanding.

“If we want to know what kind of heart we have, we need to look to our affections.”

If you go to a football game, it’s by means of your understanding that you identify the team in purple and gold as the Vikings, and the team in green and yellow as the Packers. But it’s by means of your will that you shout and cheer for the Vikings and boo and hiss at the Packers. Crucially, it’s the inclination of the will that governs our actions. Now, some inclinations of the will are mild and minor; they barely register at all (like choosing what socks to wear today). But other inclinations of the will are vigorous, persistent, and lively (like choosing whom you’re going to marry). Only the latter are termed affections. They are the more vigorous and sensible exercises of the will.

3. Importance of Affections

Why are affections so important? Affections are often the spring of men’s actions. They make the world go round. Without lively affections, few of us would do much of anything. What animates our actions is our loves and hates, our fears and desires, our griefs and joys. More importantly, affections reveal the fundamental orientation of the heart. When you see what a person loves, hates, fears, desires, rejoices in, and grieves over, you’re seeing the bent and tendency of his heart. So if we want to know what kind of heart we have, we need to look to our affections.

4. Evaluating Affections

It’s important, however, that we don’t make a mistake in evaluating our affections. Edwards is clear that we should focus primarily on the fixity, persistence, and strength of our habitual affections, rather than on the immediate intensity of any particular affection. Clarity will keep us from evaluating ourselves (and others) wrongly. A flash of emotion doesn’t tell us much one way or another. Nor should we measure the strength of our affections by the immediate outward effects (some of which are determined by personality and culture). Rather, we should mainly be concerned with the strength of our habitual affections, the tendency of our hearts over time and through challenges. This will keep us from jumping to premature conclusions because we have an unusually bad day (or an unusually good one).

5. Unreliable Signs

We need to be clear about what Edwards means by unreliable signs. Unreliable signs are not bad; they’re simply unreliable. In other words, the presence of an unreliable sign in your life isn’t defective; it just isn’t decisive. It doesn’t count against you, but neither does it count in your favor. In that sense, unreliable signs don’t tell us much. For example, intense affection is an unreliable sign. On the one hand, intensity could be good. Think of David in the Psalms. On the other hand, people have intense affections for all sorts of reasons that have nothing to do with Christ. Likewise with physical manifestations. When the prophets encounter the presence of God, they fall on their faces. This is good and right. But people faint at political rallies and rock concerts. So we shouldn’t put too much stock in physical manifestations of intense emotion.

Essentially, an unreliable sign is capable of being counterfeit. Edwards’s rule of thumb is this: if unbelievers can do it, it’s not reliable. If the devil can imitate it, it’s not reliable. So we shouldn’t fear or reject unreliable signs. Neither should we bank on them.

6. Reliable Signs

When it comes to the twelve reliable signs, they follow a distinct progression, and they can be clustered together into groups. Over the years, I’ve found it helpful to think of them as a tree. The first four signs are the roots. They are foundational to the tree, but often hidden and difficult to discern (especially in others). True affections are the result of a saving work of the Spirit that gives us a new sense of the heart, a new foundation in our soul. This new sense is able to see the moral excellency of divine things, the beauty of God’s holiness, which gives rise to a distinct kind of knowledge of God. Just as there’s a difference between knowing that honey is sweet (because you read it in a book) and actually tasting the sweetness of honey for yourself, so also there is a difference between knowing that God is holy (even the demons know that) and actually tasting the sweetness and delight of his holiness. It’s this deeper, experiential knowledge that God gives us in the new birth, and this knowledge is essential for genuine religious affections.

“True affections are the result of a saving work of the Spirit that gives us a new sense of the heart.”

From the roots we move to the trunk in signs five to seven. True religious affections are “attended with” these signs. There’s a conviction of God’s reality that comes from a direct encounter with him through his word. We know Christ is real because we’ve tasted and seen his beauty for ourselves. Likewise, this sight of God’s holiness and beauty humbles us, since we become more aware of our own abiding sinfulness. We don’t just regret our sins because we might be punished; we loathe our sins because they are odious and disgusting. Finally, this sight of divine glory in the gospel transforms our very nature.

Out from the trunk come the branches of signs eight to eleven. These signs begin to be more visible. Our new nature reflects Jesus in his love, meekness, and mercy. Our hearts are softened and our consciences made sensitive to remaining sin. Our pursuit of holiness is comprehensive; we don’t simply pursue certain virtues to the neglect of others, but instead seek to show all of the fruit of the Spirit. What’s more, we don’t rest satisfied in our progress thus far, but are continually striving for more of God and holiness, more of love and grace.

The final sign, Edwards says, is the most important. It’s where all the other signs have been leading. The final sign, out on the branches, is the fruit of a holy life. We know trees by their fruit, and in this case, that means a universal, earnest, and persevering obedience to Jesus. Universal doesn’t mean perfect; it means that there is no area of our life off-limits, no pet sins that we keep untouchable. We seek to obey the Lord in every way that we can, and in doing so, we show the fruit of the grace that we have tasted and that has transformed us from the inside out.

7. Testing Edwards’s Insights

It’s worth noting that it’s possible to disagree with Edwards in his emphasis in certain signs. For example, in my own experience, I’m not sure that his counsel on humility in the sixth sign is always helpful. While I agree with his basic point — there’s a difference between legal humiliation (which makes us feel sorrow because we’re being punished) and evangelical humiliation (by which we’re sorry because we’ve grievously sinned) — Edwards’s exhortation to continually evaluate one’s pride to make sure you’re not taking pride in your humility or in your awareness of your pride in your humility can be debilitating. You can easily get stuck on a treadmill of introspection and lose yourself in navel gazing. And this is just an example. Edwards, for all of his wisdom and biblical insight, is still human, and it’s good to test what he says by the Scriptures and to evaluate his applications by wisdom.

8. Body, Circumstances, and Sin

As you read the signs, it’s important to remember that Edwards recognizes the role of the body, our circumstances, and sin in hindering our affections and our assurance. Alterations in the body can affect our imaginations, our minds, and our emotions. Depression (what Edwards calls melancholy) is real, and has a bodily aspect that can influence our thoughts and emotions. In fact, Edwards says, Satan takes advantage of these bodily weaknesses to prey upon weary and depressed saints. This means that a full prescription for someone in depression will include both spiritual counsel and bodily help. While Edwards focuses primarily on the spiritual dimension, he certainly recognizes the role of the bodily dimension. And so should we.

“Assurance comes not by looking inward, but by action, by looking to Christ and living out of what you see.”

Likewise, pay attention to the beginning of part 3, where Edwards notes the way that circumstances and sin can rob us of assurance of salvation. Those who are low in grace and have fallen into deep sin should not expect to have assurance of salvation. The lack of assurance is a mercy from God, meant to drive us to repent and seek him wholeheartedly. For the one who is low in grace, God seems hidden, as though covered by a dark cloud. What’s more, being low in grace, our spiritual eyesight is dim, and the combination of dark clouds and bad eyes means that we cannot see his smiling face. No amount of signs written in a book will overcome the frustration and fear in such a case. The only remedy is turning to Christ afresh and growing in grace.

9. Seeking Assurance

The previous item leads to an absolutely crucial statement that Edwards makes for those who are struggling with assurance. If you find yourself low in grace and in assurance, doubting and fearing that you don’t truly belong to God, what should you do? Let’s make it more concrete. If reading this book devastates you and you wonder what you should do, remember this quotation from Edwards:

’Tis not God’s design that men should obtain assurance in any other way, than by mortifying corruption, and increasing in grace, and obtaining the lively exercises of it. And although self-examination be a duty of great use and importance, and by no means to be neglected; yet it is not the principal means, by which the saints do get satisfaction of their good estate. Assurance is not to be obtained so much by self-examination, as by action. Religious Affections, 195)

The way to grow in assurance is to kill sin, seek God’s grace, and exercise it as much as you can. Assurance comes not by looking inward, but by action, by looking to Christ and living out of what you see.

10. Humble Posture

The final item is less about the book itself and more a piece of pastoral advice. Read this book humbly. Don’t mainly read it so that you can evaluate the genuineness of others. Edwards, in fact, says that, while we can make a general judgment about the authenticity of others, we can’t infallibly and certainly know that another person is truly born again. We can’t see the heart. Ultimately, only the Lord knows those who are his. Nevertheless, we can have real assurance of our own standing with God, and this book can serve that assurance by directing our attention in the right directions.

If we read humbly, if we read carefully and wisely, if we read in community with others and under the guidance of wise pastors and counselors, then this book can be more than devastating. It can be a means of grace, a gift from God, one that leads you to truly know and deeply treasure all that God is for you in Christ.