Redefining Sin

In his book Every Good Endeavour (2012), Tim Keller, founder of The Gospel Coalition and prominent New Calvinist, expresses his disappointment that Christians are not more involved with popular culture. He writes: ‘Christians’ reaction to popular culture in the last eighty years has been some form of disengagement… Why this disengagement with our culture? One reason is a “thin” or legalistic view of sin, where sin is seen as a series of discrete acts of noncompliance with God’s regulations. You pursue Christian growth largely by seeking environments where you are less likely to do these sinful actions… This view of sin comports with a lack of understanding of the thoroughness and richness of Christ’s gracious work for us… If we have a thin view of sin, we will feel safe if we remove from our view anything that could tempt us to commit actions of overt sexual immorality, profanity, dishonesty, or violence.’[i]

 A thin view of sin

Keller is defining thin sin ‘as a series of discrete acts of noncompliance with God’s regulations’. So a discrete act of adultery, theft or murder, is what Keller labels a ‘thin sin’.  He says that Christians, who hold such a view of sin, are ‘legalists’ who withdraw from the popular culture of the world in order to avoid situations that could tempt them to commit ‘thin sins’, like overt acts of sexual immorality, profanity, dishonesty, or violence. In Keller’s thinking, the Lord Jesus held a legalistic, thin view of sin, for when he taught his disciples about sin, he listed a number of discrete acts. Jesus said, ‘What comes out of a man, that defiles a man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, thefts, covetousness, wickedness, deceit, lewdness, an evil eye, blasphemy, pride, foolishness. All these evil things come from within and defile a man’ (Mark 7.20-23).

Here we should note the biblical definition of sin.  The Bible describes sin as breaking God’s law. ‘Whoever commits sin also commits lawlessness, and sin is lawlessness’ (1 John 3:4). It is also defined as rebellion against God (Deuteronomy 9:7), which separates the sinner from God (Isaiah 59.2). Sin is an offense to God’s holy character and all sin is primarily sin against God.

The Westminster Confession of Faith declares: ‘Every sin, both original and actual, being a transgression of the righteous law of God, and contrary thereunto, doth, in its own nature, bring guilt upon the sinner, whereby he is bound over to the wrath of God, and curse of the law, and so made subject to death, with all miseries spiritual, temporal, and eternal.’ (VI, 5-6)

Keller argues that those who hold a thin view of sin (a series of discrete acts of noncompliance with God’s law) do not really understand God’s grace, and therefore believe that they must earn their own salvation.  But Keller assessment is completely wrong, for it is those who hold what he calls a thin view of sin who have been convicted of their sin and rebellion against God’s holy law, and understand that their only hope of salvation is God’s grace revealed in the Cross of Christ. Hence their prayer: ‘Nothing in my hand I bring, simply to thy Cross I cling’. Born again Christians, who have been sealed by the Holy Spirit and stand in God’s grace for their salvation, are those who delight in God’s moral law and seek to obey it with all their heart, and do all they can to comply with what Keller calls ‘God’s regulations’.

 A thick view of sin

Having disparaged a thin view of sin, Keller encourages his readers to adopt what he calls a ‘thick’ view of sin that allows them to engage with popular culture. He writes: ‘The complex, organic nature of our sin will still be at work making idols out of good things in our lives—such as our moral goodness, financial security, family, doctrinal purity…  But too much emphasis on wholesale withdrawal from culture increases the likelihood of slipping into other more “respectable” idolatries.  A theologically “thick” view of sin, by contrast, sees it [sin] as a compulsive drive of the heart to produce idols. This view should lead neither to withdrawal nor to uncritical consumption, but rather to humble, critical engagement with culture.’

Keller’s thick view of sin encourages Christians to engage with worldly culture, because ‘withdrawal from culture increases the likelihood of slipping into other more “respectable” idolatries’, like a love of moral goodness and doctrinal purity.  Indeed, engagement with worldly culture is supposed to help Christians overcome the ‘compulsive drive of the heart’ that produces ‘respectable’ idols of good things. Keller’s ‘compulsive drive of the heart’ appears to be an inner force over which Christians have little control, like Freud’s unconscious motivation that drives human behaviour.  It follows that those Christians, who withdraw from the world and seek to live a moral live, are in danger of succumbing to the ‘compulsive drive’ to turn their desire to lead a moral life into an idol, and so fall into ‘thick sin’.

But Scripture makes no distinction between thick and thin sin. It teaches that sin comes from the lusts and desires of the human heart that is desperately wicked. ‘But every man is tempted, when he is drawn away of his own lust, and enticed. Then when lust hath conceived, it brings forth sin: and sin, when it is finished, brings forth death’ (James 1.14-15).

Keller’s classification of sin into thin and thick is entirely without scriptural authority, and purely a figment of his foolish imagination; it is profoundly heretical, for it presents a false and misleading view of sin that downplays the wickedness of disobedience to God’s moral law, suggesting that Christians should engage with the world in order to overcome what Keller calls ‘the compulsive drive of their heart to produce idols’. Those who seek after moral goodness and love sound doctrine are, of course, born again Bible-believing Christians, who Keller views as fanatics (Reason for God, pages 56-57).


We must conclude that Keller is promoting a false version of Christianity that adopts a thick view of sin; a view that encourages Christians to engage in worldly conduct and downplays the importance of holy living. Yet Scripture warns that friendship with the world is enmity with God. ‘Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God?’ (James 4.4)  Christians must not conform to the pattern of the world.  ‘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. For all that is in the world—the lust of the flesh, the lust of the eyes, and the pride of life—is not of the Father but is of the world.  And the world is passing away, and the lust of it; but he who does the will of God abides forever’ (1 John 2.15-17).

Keller’s redefinition of sin undermines the true Faith by persuading Christians that obedience to God’s moral law is not really that important. He  goes so far as to claim that those who believe that discrete acts of sexual immorality or dishonesty are sinful, are actually legalists who don’t understand the real meaning of grace, just like the Pharisees.  In blatant defiance of Scripture, Keller encourages Christians to engage with the world’s culture, in order to avoid ‘respectable’ idolatries.  But God commands his people to be separate from the things of the world. ‘Therefore, “Come out from among them, and be separate”, says the Lord, “And I will receive you”.’ (2 Corinthians 6.17).

You can learn more about Dr Tim Keller, Pastor Mark Driscoll and Pastor John Piper in the book, The New Calvinists (2014), published by The Wakeman Trust and Belmont House Publishing. The book is available from The Metropolitan Tabernacle bookshop or from Amazon



[i] Tim Keller, Every Good Endeavour, Hodder & Stoughton, 2012, pp192-93