Gospel-centered sanctification will lead to lawlessness.
Wasn’t this the objection of the Catholic Church when Luther proclaimed justification through faith alone? They objected that if people were taught that they would be saved simply through faith, they would leave off the mass, almsgiving, prayers, confession, and all other good works and sacraments. To this we all object that the Gospel in justification does not keep us from doing what God commands, but all the more motivates us to do what God’s Word teaches. And why not so in sanctification as well as justification? If the recognition that I can offer God nothing that will gain me merit in my justification does not lead to lawlessness, then why should the same recognition in regard to my sanctification do the same? No one is looking to make grace abound because of sin, rather, we look to the Gospel as the powerhouse of sanctification. Being good and glorifying God does not result from my intense self-discipline. It is a result of the Gospel. The more I come to see His righteousness in my place, the more I will be motivated, no, find the power, to live out who I really am in Christ.
Unity cannot be achieved around the Gospel; unity must be achieved through doctrinal affirmation.
To some extent, our problem, once again, is a flawed understanding of the doctrine as it has been presented. When referring to the Gospel, we are not simply referring to the concept of justification through faith alone (the simplistic view), but rather the fact that the whole of Christian doctrine finds its source in the Gospel and the whole of Scripture focuses on the Gospel. For example, how do we learn that God is love outside the Gospel (I John 4:10)? How do we worship without an understanding of the Gospel (“Word of Christ” – Col. 3:16)? What was the purpose of the prophecies and the moving of the Holy Spirit in the work of inspiration but to proclaim the Gospel (I Pet. 1:9-12)? Through the lens of the Gospel, there is no doctrine, whether eschatology, anthropology, ecclesiology, hamartiology, or even angeology, that remains untouched. So when a pastor calls his people to Gospel unity, he does not call them to unify around justification through faith alone (and thus to unite with Pentacostals, Presbyterians, Methodists, Luthrans, Baptists, and cool church up the block), he rather calls them to unity around the full implications of the Gospel in every area of doctrine that it touches (which is essentially analogous to the fundamentals of the faith).
It’s all about Calvinism.
This objection is often presented because the chief proponents of the movement are Calvinists. On a surface level, this statement seems to have much merit, but in reality it is quite lacking. Should we reject the teachings of Luther because of his “Calvinism”? Should we burn our copies of Pilgrim’s Progress? Should we ignore the contributions of men like Jonathan Edwards? No! Should we reject the use of Nouthetic counseling? Just because someone may believe in what may or may not be a flawed system, it does not negate the entirety of their dogma. In other words, this objection is flawed because it attempts to negate the doctrine by questioning another aspect its sources rather than wrestling with the argument.
The gospel is just about justification, getting saved, or evangelism.
The majority of the writers on the subject (Piper, Keller, Chapell, etc.) have been quite clear in their objections to this point. The whole purpose of their writings on the topic is to assert that the Gospel is to be central not only in justification but also in sanctification. As defined by these and other writers, the Gospel is that doctrine that teaches that we are unable to merit God’s favor due to sin, that we must come to God simply through faith in His Son, and that God, through Christ, gives us everything we need for life and godliness. This objection is flawed because it fails to understand the source material on the topic.
For a further explanation see my pastor’s brief introduction to the topic here.