frank charles thompson, says that the main theme of ephesians is to tell the newly converted jews not to separate themselves from their gentile fellow christians. the unity of the church, especially between jew and gentile believers, is the main thing in the book. the purpose of the epistle, and to whom it was written, are matters of much speculation. it was regarded by c.h. dodd as the "crown of paulinism." meaning the most important part of paul's teachings.