Author: John Piper

Christian Hedonism asserts that the most effective way to kill our own sin is by the power of a superior pleasure. No one sins out of duty. We sin because it is more pleasant or less painful than the way of righteousness. So bondage to sin is broken by a stronger attraction — a more compelling joy.

Two hundred years ago, Thomas Chalmers (1780–1847) wrote one of the most famous defenses of this truth. It was called “The Expulsive Power of a New Affection.” We believe you would profit from knowing the man and this remarkable message.

He Created an Era

Converted to Christ while already in the pastorate (1810) in Kilmany, Scotland, Chalmers eventually became professor of moral philosophy in the University of St. Andrews, and then professor of theology in the University of Edinburgh.

His influence in church and politics in Scotland was so extensive that according to geologist Hugh Miller, Chalmers “may be said to have created than to have belonged to an era.” And William Gladstone, Britain’s foremost political leader of the century, called him “a man greatly lifted out of the region of mere flesh and blood” (Mark Noll, “Thomas Chalmers in North America,” 763). On his death, one estimate was that half the population of Edinburgh attended his funeral (764).

During his professorship at St. Andrews, his passion for global missions was so inspiring that six of his best students dedicated themselves to missions, resulting in 141 years of combined missionary service (St. Andrews Seven).

Blood-Earnest About Joy

Though he was influential in geology and astronomy, Christian apologetics, relief for the poor, economics, Calvinistic orthodoxy, and ecclesiastical leadership (helping create the Free Church of Scotland), nevertheless, it was the force of his words that gave effect to all of these engagements.

According to A.C. Cheyne, his oratorical power “bordered on wizardry” (Noll, 764). William Wilberforce wrote in his diary in 1817, “All the world [is] wild about Dr. Chalmers” (762). But why? Princeton’s James Alexander asked John Mason on his return from Scotland why Chalmers was so effective, and Mason replied, “It is his blood-earnestness” (Thoughts on Preaching).

If you ever read his most famous message, “The Expulsive Power of a New Affection,” let that tone — blood-earnestness — shape the way you read. Don’t think he is trifling. He is very serious. Joyfully serious.

Expulsive Power

I recall once being asked a trick question: If you had access to all the latest machinery in a sophisticated science lab, what would be the most effective way to get all the air out of a glass beaker? One ponders the possible ways to suck the air out and create a vacuum. Eventually, the answer is given: fill it with water.

That is the point of Chalmers’s famous message. It is intended as an illumination of 1 John 2:15:

Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him.

Chalmers poses for himself the question: How shall the human heart be freed from its love for the world? (How shall the air of world-love be removed from the soul-beaker?) This “love” is not a duty one performs. It is a delight one prefers. It is an affection before it is a commitment.

He says there are two ways one might seek to remove this controlling affection from the heart. One is to show that the world is not worthy of our affection and will let us down in the end. (This argument corresponds to using a pump to suck the air out of the beaker.)

The other is to show that God is vastly more worthy of the heart’s attachment, thus awakening a new and stronger affection that displaces the former affection for the world. (This corresponds to pouring water into the beaker to displace the air.) Hence “the expulsive power of a new affection.” Chalmers himself states his purpose,

My purpose is to show that from the constitution of our nature, the former method is altogether incompetent and ineffectual and that the latter method will alone suffice for the rescue and recovery of the heart from the wrong affection that domineers over it.

Rooted in Reality

Don’t miss the words “from the constitution of our nature.” He’s going to make his point by arguing “from the constitution of our nature,” not from an exposition of the biblical text. This is why I said above that this sermon (or was it a lecture? — we have lost the historical setting when it was delivered) is intended as an illumination (not an exposition) of 1 John 2:15.

Chalmers could do biblical exposition. But he was a scientist and a philosopher, as well as a preacher of biblical texts. His apologetical contribution, that made him so popular in his day, was to show that biblical morality was rooted not just in religious authority, but in the profound realities of the way things really are in the world.

This is what he means by saying, he is going to argue “from the constitution of our nature.” In other words, he will appeal to what ordinary unbelievers can actually see about the way their hearts work.

Nature Hates a Vacuum

Without taking away the excitement of your own discovery of how Chalmers argues from the nature of our souls to the biblical reality of 1 John 2:15, I will give you one enticement for you to ponder as you read. One of his central insights about the “constitution” of our nature is that nature hates a vacuum. This is why we can’t create as good a vacuum in the beaker with a pump as we can by pouring water in. The empty beaker fights back. It hates being empty. It demands content.

So it is with the human heart, Chalmers argues:

Such is the grasping tendency of the human heart, that it must have a something to lay hold of — and which, if wrested away without the substitution of another something in its place, would leave a void and a vacancy as painful to the mind, as hunger is to the natural system.

This is why Chalmers thinks it is futile to try to suck sinful pleasures out of the human heart with the pump of fear, if we do not put a better pleasure in their place. One might think that humans have the capacity to use willpower and resolve to stop loving the world, but according to Chalmers, “Even the strongest resolve is not enough to dislodge an affection by leaving a void.” That, he argues, is “the constitution of our nature.”

From His Joy

Chalmers stays true to his purpose. He makes his case from “the constitution of our nature.” If we look in the Scriptures for illustrations of Chalmers’s point, the first place I would go is to Matthew 13:44:

The kingdom of heaven is like treasure hidden in a field, which a man found and covered up. Then from his joy he goes and sells all that he has and buys that field.

This little parable assumes that until this man found the treasure of the kingdom he was enjoying “all that he has.” Then something happens. He discovers a reality that awakens a new affection. This new affection expels the old affections. His enjoyment of “all that he has” loses its dominion because of “the expulsive power of a new affection.”

“The expulsive power” is evident in the words “from his joy.” “From his joy he goes and sells all that he has and buys that field.” The power at work to drive out the old affections (the love of the world) is a new power. This power is “from his joy.” The expulsive power is coming from somewhere. It is coming from a new “joy.” Joy is the new affection. And it is functioning in this parable exactly as Chalmers describes.

It should not surprise us that a true description of “the constitution of our nature” (Chalmers) and a true insight into Scripture (1 John 2:15; Matthew 13:44) reveal the same truth. We call it the sin-killing power of Christian Hedonism. The root power of sin is severed by the power of a superior pleasure. The bondage to sin is broken by a stronger attraction — a more compelling joy. Or, as Chalmers says, “The expulsive power of a new affection.”

Joy in Christ is not passive or timid. It severs, with holy aggression, all boasting and self-pity still within us.Watch Now