20 years ago, I took a class in college called "Methods and Research" (501), and I am certain that Dr. Warnock took a similar class after he completed his undergrad equivalent. In that class, you learn really two things:  How to find facts, or substantiate them, and  how to cite your sources so that others can track them down and you can legitimize your findings.
I say that to draw attention to Dr. Warnock's citation:
(Quoted in Eusebius pages 209-210)Now, technically, Dr.
Eusebius, I am sure you know, was a 3rd century Bishop who didn't write any books -- at least, not as we count them as books. So Eusebius didn't publish anything with page numbers. And there is no extant work named "Eusebius" which yields us the quote Dr. Warnock has posted.
The correct citation of this quote, FWIW, is The History of the Church from Christ to Constantine, which is actually written by Eusebius, and the on-line edition is found at Google Books, edited by G.A. Williamson, pg 153, and it is Eusebius citing Irenaeus on the continuation of the gifts in a work we know as Against Heresies. And sadly, for Eusebius, Dr. Warnock's source, and Dr. Warnock, this passage does not appear in Irenaeus at all.
I'd be glad for Dr. Warnock or his source to prove for us otherwise.