The macabre image, which now appears, graphically conveys the revolting nature of the world’s persecution of the church. That the world should persecute the church is one thing, but that it should find such pleasure in doing so is another.
There is nothing the world and this present culture loves more than the belittling and the destruction of the truth and of the church. You get it constantly, through the media, everywhere: the vaunting of materialism, and the scorn and derision of things spiritual and Christ and the church. And this is what is meant here. She's drunken with the blood of the saints. She's happy with every persecution she can launch, and every campaign.
False religion always persecutes the church. In the Old Testament Judaism was an offence to the pagan nations. Why were New Testament believers attacked? Because they were hated on account of the gospel. So today humanism is incensed against the people of God. False religion is international. Every nation has a religion even if it is humanism.