This article is an extract from the book The Pied Piper: Is John Piper and 
New Calvinism Destroying the Church by Enoch Burke (Burke Publishing, 2018).
Matthew Henry, the nonconformist Bible commentator of the 17th century, wrote regarding sexual sin: “Can anything be more inconsistent with our profession or relation? …The sin of fornication is a great injury in a Christian to his Head and Lord, and a great reproach and blot on his profession. It is no wonder therefore that the apostle should say, “Flee fornication (1 Cor. 6:18), avoid it, keep out of the reach of temptations to it, of provoking objects. Direct the eyes and mind to other things and thoughts.” Alia vitia pugnando, sola libido fugiendo vincitur—Other vices may be conquered in fight, this only by flight; so speak many of the fathers.”
When I served as leader of the Christian Union on the campus of NUI Galway, we held many public talks throughout the year on subjects ranging from the reliability of the Scriptures to the problem of pain in a world which God created. Towards the end of the academic year, the Students’ Union on campus put a motion to the entire student body. This motion, if successful, would mandate the union to push for “same-sex” marriage nationwide. As students, and members of the Students’ Union, this was something we could not countenance. We covenanted, as the Christians on campus, to mount a simple counter-campaign.
Never have I seen such opposition to Christianity as I saw following the 
launch of our campaign. Our table on the main concourse of the college was vandalised within hours, and practically all our posters ripped down. Members of the Christian Union were physically intimidated and the object of vitriolic abuse and threats in person and on social media (one user said I should be doused in petrol and set alight). The fury of hell was vented against our message that marriage was a lifelong union between one man and one woman. We had touched a raw nerve and the devil’s wrath was unleashed. Even a year later, students who had observed us on the day continued to comment publicly on how badly we had been treated.
Men of God throughout the ages have acknowledged that any true work of God will bring opposition. Paul, however, makes that great statement of the twofold Christian influence: “to the one we are the savour of death unto death; and to the other the savour of life unto life” (2 Cor. 2:16). In 1791, John Wesley warned Wilberforce that unless God endued him with power for the battle against slavery, he would be “worn out by the opposition of men and devils.”
Fruit: The Practical Effect of Teaching
Christ commands in Matthew 7:15 to “beware of false prophets” but follows up with an instruction as to how we are to keep His command: “ye shall know them by their fruits” (Mt. 7:16). Testing the prophets (or teachers) of our day is not a complicated task beyond the reach of the Christian, but a command which Christ expects and empowers us to fulfil.
The word fruit in the New Testament, karpos, means fruit, produce or crop. It is used widely all throughout the New Testament, especially in the gospels. The Brown, Fausset and Jamieson Commentary notes that by fruits is meant “not their doctrines—as many of the elder interpreters and some later ones explain it—for that corresponds to the tree itself; but the practical effect of their teaching, which is the proper fruit of the tree.”
Measuring, or assessing, the “practical effect” of the teaching of John Piper and other New Calvinists is thus commanded by the Lord Jesus Christ and the duty of every Christian.
There is no doubt that the teaching of John Piper and other New Calvinists is bearing fruit, i.e. is having a practical effect on the church. That is not to say that it is having a favourable effect, for the evidence shows an extremely negative impact, when measured against the rule of God’s 
Word. Nonetheless, even the secular media has recognised that New Calvinism is having an impact: a landmark article published in Time magazine included “The New Calvinism“ in its “Ten Ideas Changing the World Right Now” and mentioning a trio of leaders: “the pioneering new-Calvinist John Piper of Minneapolis, Seattle’s pugnacious Mark Driscoll and Albert Mohler, head of the Southern Seminary of the huge Southern Baptist Convention.”
One significant example of change fostered by New Calvinism is found in Piper’s attitude towards sexual sin: Piper and his contemporary New Calvinists discuss the subject in-depth, with almost no topic off-limits, conversing ad lib on a whole array of sexual subjects which the Scripture says ought not to be mentioned.
Piper’s Unscriptural View that Guilt, Not Sin, is the Problem
When one examines the core of Piper’s message on sexual sin, it becomes clear that a different message from that of preachers in generations gone by is being articulated. Piper assumes that young Christians will be sinning sexually and tailors his message to that end. A close examination of his writing reveals that, to Piper, the main tragedy of sexual sin is not the offense which it causes to God but the guilt which it leaves in the conscience. Piper explicitly states such heresy over and over in his sermons and articles.
An example of this is found in an article which Piper penned in 2007. 
Writing in Christianity Today, he titled his article: “Gutsy Guilt: Don’t let shame over sexual sin destroy you.” In his article, Piper declares: ‘The great tragedy is not … fornication or pornography. The tragedy is that Satan uses guilt from these failures to strip you of every radical dream you ever had or might have.”
Here, Piper seems far more concerned to combat the effects of sexual sin than to condemn the heinousness of the sin itself. Ultimately, he teaches a psychological soothing of the guilt of sin while downplaying its seriousness.
Piper’s use of emotive language, with an emphasis on liberation (“seeing Jesus”) and “Christian” hedonism, counters Scripture’s clear pronouncements on the gross error and tragedy of sexual sin. His message is attractive to young people, many of whom have no genuine experience of salvation, or are backslidden and are attracted by the pleasures of the world. The practical effect of Piper’s preaching is to leave Christians, especially Christian young people, with less fear of sexual sin, and less inhibition in persisting along its path. This is a snare to the church, not a blessing, a ploy which will sap its youth of strength, and a cancer which will eat out the vitals of Christian testimony.
Piper’s statements on sexual sin are wholly unscriptural. In 1984, he stated regarding sexual sin that “Periodic failure in this area no more disqualifies you from ministry than periodic failures of impatience.” Proverbs, however, repeatedly associates sexual sin with spiritual death. Proverbs 7 warns regarding the harlot that “she hath cast down many wounded: yea, many strong men have been slain by her; her house is the way to hell, going down to the chambers of death” (7:26-27). The guests of the harlot are portrayed as being in the depths of hell (Pro. 9:18) and there is a certain doom repeatedly attached to their destiny: “He that doeth it destroyeth his own soul; a wound and dishonour shall he get; and his reproach shall not be wiped away” (6:32-33).
A faithful holding forth of the word of God will testify to the full seriousness of sin as revealed in Scripture. Sexual sin, according to the book of Proverbs, leaves stains impossible to remove: “His own iniquities shall take the wicked himself, and he shall be holden with the cords of his sins; he shall die without instruction; and in the greatness of his folly he shall go astray” (5:22-23). While there is hope for any repentant sinner, the emphasis in Scripture is always on judgment when it comes to sexual sin.
This new approach to sexual sin is a philosophy that runs like a thread through all of Piper’s teaching and is not an isolated doctrine. Speaking at the Passion Conference in Atlanta in 2007, John Piper again reiterated his philosophy. He stated regarding young people: “the great tragedy is not mainly…fornication…the tragedy is that Satan uses the guilt of these failures to strip you of every radical dream you ever had.” Piper accomplishes a subtle shift in emphasis here, moving his condemnation away from the sin itself to the effects of the sin. Piper states explicitly in the same speech: “my aim is not mainly to cure you of sexual misconduct…you need to fall on your face and plead that God would open your eyes to see the compelling glory of Jesus Christ.”
Piper’s words reveal a move away from the scriptural view of sin, however. Curing sexual misconduct ought to be the aim of every preacher, for curing the sinner of his sin was the reason for Christ’s coming (Mt. 1:21), and sin is the “transgression of the law” (1 Jn. 3:4). The power of Christ’s gospel is seen in the sinner being cured of sexual misconduct, and all other transgressions of God’s law.
The Consequences of Taking Sin Lightly
Any departure from the clear doctrines of Scripture amounts to spiritual poison, and poison has harmful consequences. Piper’s words have the effect of downplaying 
the slavery inherent in sexual sin, and the curse on those who persist in it. Furthermore, in downplaying these realities, he downplays the fear of sin in those who listen to him, and thus does them spiritual harm. In this regard, he is guilty of the same sin as those teachers mentioned by the Apostle Peter: “they allure through the lusts of the flesh, through much wantonness, those that were clean escaped from them who live in error; while they promise them liberty, they themselves are the servants of corruption: for of whom a man is overcome, of the same is he brought in bondage” (2 Peter 2:18-19).
With Piper, one hears little of the vengeance of God against those who indulge in the sin of the age (Rev. 21:8), or the attitude which God commands that the church adopt towards such sin in its midst: “put away from among yourselves that wicked person” (1 Cor. 5:13). Sexual sin is singled out in Scripture for particularly vigilant avoidance: “Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body” (1 Cor. 6:18). This is the sentiment that any faithful preacher will urge upon his congregation. The first step of entanglement in such sin has fearful consequences: the church therefore should flee the voice of strangers such as John Piper (Jn. 10:5) and remember that if one becomes ensnared, “the last state of that man is worse than the first” (Mt. 12:45).
Conclusion
As the fictitious Pied Piper lured the unsuspecting children of Hamelin to promised good fortune, so also John Piper lures many to a lighter view of sin, a lighter view of holiness, and a lighter view of the reality of God’s wrath. The gloss of Piper’s doctrine contains appeal for those who are not firmly acquainted with the truth, and who have not been mastered by it. The charm of Piper’s message captivates those who would escape the cost of discipleship and hear new, wrested interpretations of the things of God which are “hard to be understood” (2 Pet. 3:16).
The Pied Piper of Hamelin, however, lured his victims to their doom. 
Charmed by the music of the Piper’s flute, the children were lured from the safety of Hamelin, oblivious to the foolishness of their actions, and so perished. So also, those who follow Piper are taking a well-worn path to destruction, for to take God’s word lightly is to invite His judgment. An embrace of Piper’s doctrine is an embrace of “doctrines of devils” and a courting of eternal destruction. Young Christians should turn from the tune of this false prophet, and heed instead the exhortation of Scripture to “exercise thyself rather unto godliness” (1 Tim. 4:7) and to be an “example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity” (1 Tim. 4:12).
The above article is an extract from the book The Pied Piper: Is John Piper and New Calvinism Destroying the Church by Enoch Burke (Burke Publishing, 2018).