People like Jeffrey Dahlmer won't even compare to what is going to happen in the future. I recommend you to carefully study the Book of Revelation.
Without a sufficient knowledge of Church history the Revelation of Jesus Christ becomes a mish-mash of Hollywood science fiction and B-movie horror films which do nothing but intrigue and titillate the flesh of millions of ignorant, easily deceived professing Christians.
Jeffrey Dahmer has absolutely nothing to do with the discussion at hand. Your analogy is a red herring. Had he been a Priest or even a Baptist pastor, your analogy would have a modicum of validity.
The central theme of the Revelation is not difficult to discern.
Satan’s masterpiece was described to John as a false Church, a great whore, a murderess, unfaithful to her Lord while alleging she is Christ’s innocent virgin bride.
Yet all the world would be blind to her true identity.
All, that is, except those true Christians whom she persecuted and even put to death for exposing her true identity.
Furthermore, the false Church would have as its head an absolute monarch, a man who would be viewed by the world as a father, kindly, holy and pure, but, in fact, is the Man of Sin, the Son of Perdition, the Beast from the Abyss.
Claiming to be a devoted servant of Christ, he is Antichrist, the rival and enemy of Christ.
I would have you consider the following Scripture:
And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain from the foundation of the world.
9 If any man have an ear, let him hear.
Our Lord has revealed how we may know who has NOT been written in the Lamb’s Book of Life, i.e., the unsaved: by discerning those who worship, honor, revere, and obey the Pope of Rome.
Christians, both ancient and not so ancient, have always known the identity of Mystery Babylon and her Antichrist.
The Mystery of Iniquity was no mystery to them.
Their testimonies are alive and well in books and manuscripts preserved worldwide for the edification and education of the Elect:
Blessed is he that readeth, and they that hear the words of this prophecy, and keep those things which are written therein: for the time is at hand.
And I heard a voice from heaven saying unto me, Write, Blessed are the dead which die in the Lord from henceforth: Yea, saith the Spirit, that they may rest from their labours; and their works do follow them.
For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.