The Key of Church Discipline
"God is a righteous judge, and a God who feels indignation every day. If a man does not repent, God will whet his sword; he has bent and readied his bow; he has prepared for him his deadly weapons, making his arrows fiery shafts."
If the gospel unlocks and opens the door to the kingdom of heaven, then there must be a sense in which it locks and closes the door to the kingdom as well. This operation of the gospel is discussed in question and answer 84 of the Heidelberg Catechism. There we read that the function of the gospel to close the door is the flip side of its function to open the door. That is to say, since the gospel declares that the entrance into the kingdom of heaven is open to all who repent and trust in Christ alone for salvation (John 3:16, 35–36; Acts 2:38–39), it also declares that this same entrance remains shut to all who do not turn from their sin and rest in Jesus.
We are living in a day when many people find repugnant the idea that God would lock anyone out of His kingdom. Faithful Christians are routinely mocked and called narrow-minded and bigoted for believing that Jesus is the only way to the Father. Unfortunately, many professing Christians buckle under this intense cultural pressure and say either that there are many ways to God or that people who have not heard the gospel may somehow be saved by Christ.
Those who truly believe in the Word of God, however, cannot waver on the exclusivity of Christ (John 14:6). In fact, we must be clear that the Lord is furious at sinners who do not repent of their sin and run to Jesus for salvation. Scripture is quite clear that God is set against those who remain impenitent. As today's passage tells us, the Lord has His bow drawn and His sword sharpened, and He has them pointed toward men and women who have yet to turn from their sin (Ps. 7:11–13). Although God is certainly patient and longsuffering, He will not be content merely to aim His weapons at the unrepentant forever. Eventually, He will pour His wrath out on those who do not turn from their wickedness. His wrath is coming (Luke 3:7), and all those who die apart from Christ will feel it. Jesus alone is the means by which we are rescued from God's righteous anger (1 Thess. 1:10).
The gospel closes the kingdom to unbelievers, proclaiming that they are shut out from the Lord's favor as long as they do not bow to Christ. Faithful preachers are clear on this fact, and they do not compromise the truth of God's wrath. Yet they are also quick to plead with sinners to turn to Christ and find salvation.
Coram Deo
Dr. R.C. Sproul has often said that we must first understand the bad news if we are going to know the good news of the gospel. There is bad news for all the natural-born sons and daughters of Adam: we are under God's wrath as long as we remain impenitent. The good news of the gospel is that those who are presently under God's wrath will enjoy His salvation if they repent and trust in Jesus alone. Faithful gospel preaching means not wavering on either of these truths.