I'm saying evil is an adjective, not a noun.
I'm saying that evil acts exist and that no external supernatural force is necessary to justify the existence of evil actions. I'm saying that when we attribute evil acts to an external supernatural force, we begin to see that force everywhere - including in our family, our friends, our neighbors, and in completely innocent strangers. It gives rise to things like the Salam Witch Trails, the Spanish Inquisition, the Satanic Panic of the 1980's, and countless other examples of religious-based hysteria. All of these destroyed lives or resulted in the loss of life. That's not even accounting for the use of supernatural evil as justification for religious intolerance, persecution of the LGBTQ+ community, and the movement to make the U.S. into a theocracy.
I'm also saying that the belief in an end-time encourages people to form end-time cults, resulting in countless deaths, ruined lives, and wasted potential. These radicalized individuals are also responsible for religious-based terrorism - both domestic and foreign - which results in even more death and destruction. The irony of it all is that the Book of Revelation was a political rant about the Roman empire, and the apocalypse it describes was supposed to happen imminently - within a few years.
The theology of Christianity is broken and one of its broken components is this belief in supernatural evil. This makes it easy to ascribe all manners of problems to this evil entity, allowing people to avoid taking responsibility for their own lives and actions. Fear is a horrible motivator that only causes chaos and destruction. Fear of the devil, hell, and the end times shackles Christianity from actually doing good in the world, and instead encourages paranoia, xenophobia, and hate.