With whom the kings of the earth have committed fornication, and the inhabitants of the earth have been made drunk with the wine of her fornication. "Of the earth" is used here (as it frequently is) for the worldly as distinguished from the righteous; and the two classes mentioned indicate the universality of this faithlessness—it is not confined to any one grade of society.
As we have seen (see on Revelation 17:1 and Revelation 14:8), the figure of fornication is repeatedly used to describe faithlessness towards God. The verse, therefore, declares that this faithless portion of the Church has chosen rather to render to the world that love which is due to God, and to be connected rather with the powers of this world than to have its treasure in heaven.
The expression, "wine of her fornication," is a repetition of that in Revelation 14:8, and is derived from Jeremiah 2:7 (cf. also Revelation 16:19 and Revelation 18:3).