It seems to me that, while the principle here is correct and Christians of all denominations agree to it, the problem comes with applying it. What you have been told is a prime example of Satan at work is not what the next denomination focuses on, and vice-versa. And, by the way, I'm not seeing anywhere in your long post that the Catholic Church is the particular agent of Satan, doctrinally speaking.
The beast of the sea of Revelation is the same beast of my previous post, described in detail.
Revelation 13:1 And I stood upon the sand of the sea, and saw a beast rise up out of the sea, having seven heads and ten horns, and upon his horns ten crowns, and upon his heads the name of blasphemy.
Revelation 13:2 And the beast which I saw was like unto a leopard, and his feet were as the feet of a bear, and his mouth as the mouth of a lion: and the dragon gave him his power, and his seat, and great authority.
The beast's attributes point back to Daniel 8, which shows the origin of the beast, starting with Babylon, then Medo-Persia, then Greece, then Rome—out of which the little horn arose. The beast of the sea is none other than the little horn, the same power, but depicted later in time near the end.
Daniel and Revelation both give clear descriptors and point to Satan as the one who gave the beast its power. Again, the Reformers came to this conclusion and it was commonly accepted by other denominations, long before SDA existed. Just how it fell by the wayside could be a type of the falling away mentioned by Paul in Thessalonians.
2 Thessalonians 2:3-4 Let no man deceive you by any means:
for that day shall not come, except there come a falling away first, and
that man of sin be revealed,
the son of perdition;
Who opposeth and exalteth himself above all that is called God,
or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
It's obvious that such things are of Satan, but Revelation spells it out in clear enough terms that it is so. i.e. It's based on scripture.
