How do we know that the Gospel is true according to Revelation?

In Revelation, the truth of the Gospel is underscored by God’s judgment on ‘Mystery Babylon,’ symbolizing false religions that lead many astray. This judgment illustrates the severity of God's wrath against those who reject His righteousness. The message of the Gospel is that salvation is not through human effort but through the imputed righteousness of Christ. As the sermon notes, understanding this truth is framed within the idea that the wisdom of God reveals how sinners can stand justified before Him. The assurance of the Gospel is that those whose names are written in the Book of Life, chosen by God before the foundation of the world, will see the fulfillment of His promises and the ultimate victory over sin and death.