"And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast." Revelation 17:12
Unlike those mentioned in Revelation 13:1, these horns have no crowns. These are powers that have received no kingdom as yet, so at this point at least they are not really kings. They will someday, however, be given power "as" kings for one hour with the beast. They will then exercise political influence.
These ten horns are not regular political heads of state. It looks instead like these are the leading evangelical churches which for a short time will enjoy king-like power. They will help to form the image of the beast, replicating the authority exercised by the papacy during the dark ages.
The word "hour" here is the same word used in Revelation 14:7 where it says, "the hour of his judgment is come." It indicates a limited but unspecified period of time.
"These have one mind...." Revelation 17:13
It has become increasingly popular for churches to ignore doctrinal differences and focus on common beliefs. Denominationalism is now considered outdated as believers flock to non-denominational worship centers. The "unity of the body of Christ" is the all-important concern.
Speaking of "the evangelical Protestant denominations," Charles Beecher in the nineteenth century said, "And what do we see just ahead? Another general council! A world convention! Evangelical alliance, and universal creed!"
"When the leading churches of the United States, uniting upon such points of doctrine as are held by them in common, shall influence the state to enforce their decrees and to sustain their institutions, then Protestant America will have formed an image of the Roman hierarchy, and the infliction of civil penalties upon dissenters will inevitably result." Ellen G. White, The Great Controversy, p. 445.
"...And shall give their power and strength unto the beast." Revelation 17:13
Just as the Roman ecclesiastical system received its medieval power by the support of the ten horns of Daniel 7, so its endtime rejuvenation is accomplished by the support of the ten horns of Revelation 17. As the barbarians changed the nature of the Roman Empire, so the Evangelicals will change the nature of America.
"These shall make war with the Lamb...." Revelation 17:14
When the evangelical churches abandon the principles of Protestantism to the extent that they seek the aid of the civil power for the enforcement of their dogmas, when they push for legislation that would ultimately compel people to violate a commandment of God, they are making war with the Lamb. This hasn't happened yet, but it is predicted in Revelation 13:16, 17. See commentary on those verses.
"These shall hate the whore...." Revelation 17:16
When the vials of God's wrath are poured out upon those who have rejected God's commandments in order to keep the laws of man, it will finally be seen that the great religious union was all a counterfeit. The true character of the symbolic "woman" will be unmasked. Those who supported her will turn from her in disgust, pouring out their contempt upon her.
"For God hath put in their hearts to fulfil his will, and to agree...." Revelation 17:17
That is, among themselves. "There has been for years, in churches of the Protestant faith, a strong and growing sentiment in favor of a union based upon common points of doctrine. To secure such a union, the discussion of subjects upon which all were not agreed--however important they might be from a Bible standpoint--must necessarily be waived." The Great Controversy, p. 444.
"...And give their kingdom unto the beast, until the words of God shall be fulfilled." Revelation 17:17
"What is it that gives its kingdom to this power? Protestantism." 7BC 983.