The seven churches in Asia in the Book of Revelation. Jesus found fault with every single one, some worse than others. He nevere told one person to leave any of those churches. And they were real churches with real Christians worshipping in them. Their descendants may still be Orthodox Christians in Turkey today, I don't know; there has been a lot of persecution.
You raise a good point. Yet he did warn the specific churches, and look ... works, and it is found 12 times in the portion of Revelation (2, 3) dealing with the 7 churches.
Remember therefore from whence thou art fallen, and repent, and do the first works; or else I will come unto thee quickly, and will remove thy candlestick out of his place, except thou repent.
I can appreciate your frustration. Consider these verses.
Rev 14:9-10 9 And the third angel followed them, saying with a loud voice, If any man worship the beast and his image, and receive his mark in his forehead, or in his hand, 10 The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb:
Revelation 18:4 4 And I heard another voice from heaven, saying, Come out of her, my people, that ye be not partakers of her sins, and that ye receive not of her plagues.