Book of Revelation confuses SO MANY BELIEVERS, page-53

"The primary audiences of Revelation are Jews who belong to the seven ἐκκλησίαι, “churches,” “assemblies,” “congregations,” etc., identified in the second and third chapters of Revelation (cf. Revelation 1.4-5). Notice each assembly did not just receive the message written to it but received the letters of all the assemblies (Revelation 1.4, 2.7, etc.). Each received all the messages. Why these seven? Why are they only in Turkey? Why are none in Israel? No one knows. The best answer may be that these believers were the same Jews to whom James and Peter wrote (James 1.1; 1 Peter 1.1). Only three of the seven cities of the assemblies are mentioned outside of Revelation: Ephesus (Acts 18.19, 21, 24, 19.1, 17, 26, 35, 20.16, 17; 1 Corinthians 15.32, 16.8; Ephesians 1.1; 1 Timothy 1.3; 2 Timothy 1.18, 4.12), Thyatira (Acts 16.14), and Laodicea (Colossians 2.1, 4.13, 15, 16). The other four are not mentioned."
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https://doctrine.org/understanding-the-book-of-revelation