God is just: He will pay back trouble to those who trouble you and give relief to you who are troubled, and to us as well. This will happen when the Lord Jesus is revealed from heaven in blazing fire with his powerful angels. He will punish those who do not know God and do not obey the gospel of our Lord Jesus. (2 Thessalonians 1:6-8 NIV)
Because wickedness is not punished immediately, we may foolishly think it will not be punished eventually. Paul reminds us that since God is just, sin must be punished. Yet, God is also merciful, and has made a way of forgiveness through the Gospel, having visited the justice sinners deserve upon His Son. If we do not obey the Gospel of Christ, and spurn that offer of salvation, then the full fury of God will descend upon sinners. That it does not happen instantly is another indicator of God/s mercy—His forbearance that affords the wicked occasion to repent. Payday, however, comes someday for, “the wages of sin is death,” (Rom.6:23a). Those who are anti-God and assail the people of God will experience God’s wrath. This will bring the deliverance of God’s children. That day is the end of the age at the return of Christ—a day of “blazing fire.” Oh, sinner, obey the Gospel today! Come to Christ without delay, for tomorrow may be too late!