The question was asked, “Are the Orthodox part of the Roman Catholics in the Book of Revelation?” In brief, the answer is a resounding “yes, of course!” I was surprised when I found the above question because the Book of Revelation does not pertain to a single denomination, no matter how much various denominations of one stripe or another may desire to hijack this part of Scripture – indeed, any part of Scripture, if we come to that – to accomodate their self-serving, self-righteous agendas. It is also not non-denominational as the term is currently understood, to be crystal clear.
What is presently happening in our world is a sifting – of those who truly desire the Triune God to come and live in their hearts and souls (the Kingdom come, as our Father has intensely wanted to do since the beginning of time and for which His Son, Jesus Christ, died) and those who reject this “coming” of God – which is not the Second Coming, as many also tend to erroneously interpret this. Soon, but still not for some time yet, we will see the Churches unite and become one as Christ and His and our Father are One – the fulfilment of the Our Father prayer given to us by Christ and the fulfillment of John 17:17-26. But not only. There is more which shall be stated herewith without equivocation.
Many “good” Catholics will fall away due to that pernicious sin of old – pride – while many non-Christians who have never been baptized but who similarly desire, in all good will, that God in His Triune manifestation comes to live in their hearts and souls will similarly unite with the universal Church and become Catholic by desire until they are formally baptized. Many, especially Catholics, tend to forget this aspect of baptism into the Church. Furthermore, Catholic does not mean Roman Catholic – though some of the latter, on the one hand, seem to love to hijack the very term. Catholic means universal, although it is not universalist as those of this particular latter stripe, on the other hand, like to claim. Catholic includes the Catholics of the Eastern Church which are fully in communion with the Western Church and can indeed be considered a very welcome bridge between the Western Rite of Catholicism and the Orthodox. I also similarly wish to make clear here that it is the One, Holy, Catholic and Apostolic Church that maintains the fullness of the faith. No other.
Having said all of the above, I will state plainly and clearly: to appropriate and restrict the Book of Revelation to Roman Catholicism as insinuated in the above question is to do a disservice, intentional or unintentional, to both God Himself and the universal Church.