Henry Allan Ironside · The Book of Revelation

It is significant that, wherever Philadelphian truth has been proclaimed, the devil has raised up a counterfeit to draw people's hearts away from the truth, and so, in verse 9, the Lord speaks of those who will be manifested as the synagogue of Satan, "who say they are Jews, and are not, but do lie." The day will come when they will have to worship before the feet of those who are faithful to the Lord, and shall know that He has loved them. It is, undoubtedly, that false Judaizing system which is contemplated, whose advocates everywhere oppose the truth of grace, and seek in every way to hinder the carrying out of those principles which we have been noticing as pleasing to the Lord. In their ignorance, these teachers give up the true Christian position, claiming to be the spiritual Israel, appropriating to themselves Jewish promises and Jewish hopes, and would put the consciences of Christians under the bondage of Jewish legalism, thus really doing Satan's work.