What does Revelation 17:15 mean?

In this verse we have the angel's explanation of the imagery of a prostitute (Revelation 17:1) seen in John's vision. The waters on which she sits are "peoples and multitudes and nations and languages." Her corrupt religious system will include false religions all over the world. Some identify this eclectic religious system as the culmination of the ecumenical movement. According to this view, apostate Protestantism, apostate Roman Catholicism, and all world religions will unite and exist as one in the tribulation.

The apostle Paul advised Timothy "that in later times some will depart from the faith by devoting themselves to deceitful spirits and teachings of demons, through the insincerity of liars whose consciences are seared" (1 Timothy 4:1–2). The apostle John also predicted the rise of antichristian religion in 1 John 2:18. He wrote: "Children, it is the last hour, and as you have heard that antichrist is coming, so now many antichrists have come." Jude warned his readers that ungodly religious teachers had wormed their way into the church. He wrote: "For certain people have crept in unnoticed who long ago were designated for this condemnation, ungodly people, who pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ" (Jude 1:4).

Whether by combining all religions, the domination of a single false faith, the invention of a new one, or simply a widespread lack of spiritual truth, the apostasy that began in the first century will grow worldwide during the end times.