"The beast out of the earth is the religious system that arises out of the soulical nature of man. While we once looked about for a laser-tattooed identification number, or a microchip in the forehead to be the “mark of the beast” — was it not truly there for us to see all along, for John plainly told us, “HERE IS WISDOM. Let him that hath understanding count the number of the beast; for it is the NUMBER OF MAN and HIS NUMBER IS SIX HUNDRED, THREE SCORE AND SIX.” Now, I am aware that the King James Bible says that “it is the number of a man,” but the indefinite article “a” is supplied by the translators and is not necessarily included in the Greek, since that language has no indefinite article. It can quite well be translated without an article at all, as in Psalm 8:4, “What is man (not a man), that thou art mindful of him?” In our text the word for “man” is not Adam, but anthropos, meaning “a human being; humanity; human-kind.” It denotes the human race as against any other species of being. The Concordant New Testament correctly translates it, “for it is the number of mankind.” Anthropos is the word used in II Timothy 3:17 wherein we read, “That the man of God may be perfect, thoroughly furnished unto all good works.” “Man of God” is not referring to a particular man, or one single man, but rather to every man of God. It is a corporate expression denoting a company of men. Likewise, the number of the beast is not referring to one man; it’s every man who possesses a soulical nature capable of spawning religious attitudes, actions, traditions, and systems! Thus we see that the number of the beast that is called the number of a “man” is the number or nature of a “corporate man” or set of men and not one man we are to look for. This “man” is already here and has been here from the dawn of history! He has found a unique expression since Christ birthed His church in the earth, bringing forth in the midst of the Lord’s people another system, a beastly religious system calling itself “the church” and which bears a striking resemblance to the Lamb of God but speaks words which sound like the voice of the dragon!"
Much more in the full study:
"We have only to read carefully and prayerfully the thirteenth and fourteenth chapters of the Revelation to see the close and inspired connection between them. They are constructed on the same lines. They run parallel in their emphasis. Consider some of the similarities and contrasts. “I saw a beast coming up out of the sea.” “I saw a Lamb standing on mount Zion.” The worshippers of the beast celebrated his greatness in a hymn of praise: “Who is like unto the beast? and who is able to make war with him?” And over against this earthly song there is an heavenly: “And I heard a voice from heaven as the voice of many waters…and I heard the voice of harpers harping with their harps: and they sung as it were a new song…and no man could learn that song but the hundred and forty and four thousand, which were redeemed from the earth” (Rev. 14:2-3). It is clear that in the fourteenth chapter the Holy Spirit is drawing a companion, yet contrasting, picture to the events of the thirteenth. He sets the two companies — the followers of the beast and the followers of the Lamb — in strong and vivid contrast."
From the next study:
https://www.godfire.net/eby/rev-159.html
"The book of Revelation is full of wonderful and striking contrasts which cannot but excite the spirit of all who have ears to hear and eyes to see! The Revelation deals with the mightiest contrast that ever existed — the contrast between Christ and Adam, between spirit and flesh, between truth and error, between spirituality and carnality, between the kingdom of light and the kingdom of darkness, and between God and the devil. We meet, furthermore, with the contrast between the company of the overcomers and the carnal church systems of man, between the two witnesses and the beast, between the manchild and the dragon, between the Lamb and the beastly system, between God’s Christ and the kings of the earth, between the saints and the world, and between Mystery Babylon and the holy city, New Jerusalem. Again and again this mighty contrast is painted for us in brilliant hues and vivid scenes of divine revelation!"
"Let us note that in chapter fourteen we have a continuation of the symbolism begun in chapter thirteen. The fact that this has been generally overlooked has led to many dreadful errors in the interpretation of the scenes of this portion."