From; Ellen G. White
Babylon’s intoxicating wine

The second angel’s message announces the fall, or apostasy, of Babylon and identifies it as a false religious system. In Revelation 17:5, “Babylon is said to be ‘the mother of harlots.’ By her daughters must be symbolized churches that cling to her doctrines and traditions, and follow her example of sacrificing the truth and the approval of God, in order to form an unlawful alliance with the world.”—Ellen G. White, The Great Controversy, pp. 382, 383.

Many of the Protestant churches are following Rome’s example of iniquitous connection with “the kings of the earth”—the state churches, by their relation to secular governments; and other denominations, by seeking the favor of the world. And the term “Babylon”—confusion—may be appropriately applied to these bodies, all professing to derive their doctrines from the Bible, yet divided into almost innumerable sects, with widely conflicting creeds and theories.
GC 383.1

The great sin charged against Babylon is that she “made all nations drink of the wine of the wrath of her fornication.” This cup of intoxication which she presents to the world represents the false doctrines that she has accepted as the result of her unlawful connection with the great ones of the earth. Friendship with the world corrupts her faith, and in her turn she exerts a corrupting influence upon the world by teaching doctrines which are opposed to the plainest statements of Holy Writ. GC 388.2

This apostate religious union will manifest the arrogance of ancient Babylon in exalting itself above God and will seek to take His place in the world. The message of the second angel warns God’s people that this wicked system will depart further and further from the truth in consequence of her refusal of the light of the end-time gospel message. Only when “the union of the church with the world shall be fully accomplished throughout Christendom, will the fall of Babylon be complete.”—Ellen G. White, The Great Controversy, p. 390.