Eternal Punishment
"Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire. And if anyone's name was not found written in the book of life, he was thrown into the lake of fire" (vv. 14–15).
Acts 17:16–34 records one of several models for evangelism that we find in the New Testament. Paul appeals to the innate sense that all people have of God's requirements and existence, and then he gives a brief presentation of the gospel, including Christ's resurrection from the dead. Note how in verse 31, Paul refers to the day of judgment on which He "will judge the world in righteousness."
This thought strikes terror into the hearts of anyone who seriously considers his sin. The Judge who will administer judgment on that last day is perfect in His justice and righteousness, and if the judgment is according to His righteousness, there will be nothing arbitrary, unjust, or unfair about it. If we stand before Him on the basis of what we have done, we have no hope. Even if we have sinned only once in our lives, we have offended an infinitely holy God, and an offense of that magnitude demands an infinite retribution. Thus, in Scripture we have the doctrine of eternal conscious punishment—there is a hell into which all those who rest in their own works and not in Christ alone will be cast, and in that place they will feel God's wrath forever and ever (Rev. 20:10, 14–15).
In many ways, we all find hell a horrible thing to think about. We all know people who are very dear to us and who have given us no indication that they know Christ. Some of these people are alive, and some have already died. We find it difficult to believe that we will be eternally happy in heaven if we know that some of those whom we love are suffering in hell. But that is to look at things from a fallen human perspective. Even though we who know Christ have true affection for Him, our way of seeing the world is so tied to our earthly experience that we tend to think more about the well-being of our friends and family than the vindication of God's righteousness. But when we enjoy our final glorified state, we will be so enraptured by the beauty of our Creator and His majestic holiness that we will be able to rejoice in the fact that this holiness and justice are being revealed against the impenitent in hell, even the impenitent to whom we have been so attached. We will be able to evaluate reality apart from the influence of our fallen nature, and we will glory fully in what glorifies the Lord, including the manifestation of His holy justice (Rev. 14:7). The Light of the World will enable us to see sin for what it truly is, and so we will rejoice in its punishment.
Coram Deo
Many people believe the doctrine of eternal conscious punishment is incompatible with God's love. However, Jesus Christ—the fullest manifestation of God's love—spoke more about hell than anyone else. In fact, hell is the inevitable result of God's love for His own glory and for the love we see between the persons of the Godhead. Each person of the Trinity loves the glory of the other persons so much that He will not tolerate those who impenitently attempt to deface this glory by their sin.