He may be an authority in the Orthodox Church, but he is no authority in Judaism.
Jewish Encyclopedia says (emphases mine)
Satan has no power of independent action, but requires the permission of God, which he may not transgress. He can not be regarded, therefore, as an opponent of the Deity.
Further, the same source says (again, all emphases are mine):
This view is also retained in Zech. iii. 1-2, where Satan is described as the adversary of the high priest Joshua, and of the people of God whose representative the hierarch is; and he there opposes the "angel of the Lord," who bids him be silent in the name of God. In both of these passages Satan is a mere accuser who acts only according to the permission of the Deity.
But, after Babylonian and Persian occupation, this changes. Thus
The Chronicler (third century B.C.) regards Satan as an independent agent, a view which is the more striking since the source whence he drew his account (II Sam. xxiv. 1) speaks of God Himself as the one who moved David against the children of Israel. Since the older conception refers all events, whether good or bad, to God alone (I Sam. xvi. 14; I Kings xxii. 22; Isa. xlv. 7; etc.), it is possible that the Chronicler, and perhaps even Zechariah, were influenced by Zoroastrianism
It is in the "Apocrypha," which you Protestants reject, that we find New Testament teachings on the devil. The language is very much something we are familiar with:
The evolution of the theory of Satan keeps pace with the development of Jewish angelology and demonology. In Wisdom ii. 24 he is represented, with reference to Gen. iii., as the author of all evil, who brought death into the world; he is apparently mentioned also in Ecclus. (Sirach) xxi. 27, and the fact that his name does not occur in Daniel is doubtless due merely to chance. Satan was the seducer and the paramour of Eve, and was hurled from heaven together with other angels because of his iniquity (Slavonic Book of Enoch, xxix. 4 et seq.). Since that time he has been called "Satan," although previously he had been termed "Satanel" (ib. xxxi. 3 et seq.). The doctrine of the fall of Satan, as well as of the fall of the angels, is found also in Babylonia (Schrader, l.c. p. 464), and is mentioned several times in the New Testament.
So, the teaching of the Church and of the Protestants regarding Satan is patently "apocryphal." Just remember that by accepting the NT, you also accept its "apocryphal" demonology even if you as a group reject the "Apocrypha." The roots are Babylonian, not Judaic.
Although Satan is not mentioned in "Apocrypha" by name, it is part of the "lower-class" belief among the Jews in the pre-Messianic era to associate the devil with Satan. This belief then finds its way into the New Testament, as the JE continues:
The high development of the demonology of the New Testament presupposes a long period of evolution. In the Gospels the beliefs of the lower orders of society find expression, and Satan and his kingdom are regarded as encompassing the entire world, and are factors in all the events of daily life.
Judaism itself eventually experienced change and acceptance of the more popular view. The dates are significant.
Talmud, moreover, proves that, according to the older view (until about 200 C.E.), punishment was inflicted by angels and not by Satan. In the course of time, however, official Judaism, beginning perhaps with Johanan (d. 279), absorbed the popular concepts of Satan, which doubtless forced their way gradually from the lower classes to the most cultured. The later a midrashic collection the more frequent is the mention therein of Satan and his hosts. The Palestinian Talmud, completed about 400, is more reticent in this regard; and this is the more noteworthy since its provenience is the same as that of the New Testament.
So, what then about Church exorcism and Baptism (which includes exorcism)? It is clearly in conflict with Torah's idea of who and what Satan is. It is not even close. It is a product of latter-Judaic heterodox teachings derived from Babylon and Persia which we accept as "gospel" because it is in the Gospels, and other parts of the New Testament! But, in reality, it was a popular belief among certain sects, which included Christians.
That's why I said I have unanswered questions regarding the devil.
He may be an authority in the Orthodox Church, but he is no authority in Judaism. Jewish Encyclopedia says (emphases mine) ......
There is no doubt that many Jews in those days had unsound theology. We are told about some of them in the Bible. But there is no way you can pin this on the OT righteous, the OT doesn't teach it. You can say that many Jews had it wrong at the time. The bottom line is that your church and my church both agree on the issue.
[Jewish Encyclopedia:] This view is also retained in Zech. iii. 1-2, where Satan is described as the adversary of the high priest Joshua, and of the people of God whose representative the hierarch is; and he there opposes the "angel of the Lord," who bids him be silent in the name of God. In both of these passages Satan is a mere accuser who acts only according to the permission of the Deity.
Zech 3:1-2 : 3:1 Then he showed me Joshua the high priest standing before the angel of the Lord, and Satan standing at his right side to accuse him. 2 The Lord said to Satan, "The Lord rebuke you, Satan! The Lord, who has chosen Jerusalem, rebuke you! Is not this man a burning stick snatched from the fire?"
The natural interpretation of this would have satan correctly being an enemy of God. There were strained and wrongful interpretations, but I'm sure the OT righteous had it right. For anyone to say that this passage has satan being a "mere accuser" is ridiculous.
So, the teaching of the Church and of the Protestants regarding Satan is patently "apocryphal." Just remember that by accepting the NT, you also accept its "apocryphal" demonology even if you as a group reject the "Apocrypha."
We reject the Apocrypha as being inspired, and so they should not be included with the Holy Bible. Nobody says they are useless or "all lies" or something. Luther himself prefaced the Apocrypha with this statement:
In addition, The Bible itself sans Apocrypha is patently clear that satan is evil. I certainly didn't need the Apocrypha to come to the correct conclusion.