The dating of revelation
What kind of sense would it make for Irenaeus to refer to copies of the apocalyptic vision as “ancient,” but also maintain that the vision itself occurred almost in his own lifetime?
This problem is alleviated if we understand ἑωράθη as a reference to John himself (“he was seen”), rather than the apocalyptic vision (“it was seen”).
There are basically two conservative views as to when the book of Revelation was written: (1) it was written in the late-90s AD, toward the end of Domitian’s reign; or (2) it was written sometime prior to 70 AD, during the reign of Nero.
Scholars produce both internal and external evidence to support whichever view they hold.
What Eusebius Thought Irenaeus Said Here’s how Eusebius utilized Irenaeus’s statements: “There is ample evidence that at that time the apostle and evangelist John was still alive, and because of his testimony to the word of God was sentenced to confinement on the island of Patmos.
Writing about the number of the name given to antichrist in what is called the Revelation of John, Irenaeus has this to say about John in Book V of his Heresies Answered: ‘Had there been any need for his name to be openly announced at the present time, it would have been stated by the one who saw the actual revelation.
You could argue that both statements are sensible enough, but I think the first one makes better sense. In making this decision, we also need to consider other things Irenaeus says about the book of Revelation.
We need to remember that Eusebius himself was very unsure about the authenticity and authority of Revelation.
In setting up this quote from Irenaeus, he refers to the book as “what is called the Revelation of John,” indicating a degree of doubt as to whether John actually wrote it.