The Epistle to the Ephesians is strikingly similar to the Epistle to the Colossians, not only in thought, but also in many details of language. Another case of striking similarity between two epistles of Paul was encountered in First and Second Thessalonians. There the two similar letters were written both to the same church, though at no very great interval of time. The similarity was due to the desire which Paul felt of reiterating, with some additions and explanations, the teaching of his former letter. In the case of Ephesians and Colossians the similarity is even more easily explained. These two epistles were written to different churches at the same time. What more natural than that the same thoughts and to some extent the same words should appear in both? Only, the teaching which in Colossians is directed against a definite form of error is in Ephesians reproduced in freer, more general form. The relation between the two epistles is somewhat like that which exists between Galatians and Romans. In Galatians, the doctrine of salvation by faith appears in conflict with the opposing error; in Romans, the same doctrine finds expression, but this time in quieter, more systematic development, after the conflict is over. The similarity between Galatians and Romans is, however, not so close as that between Colossians and Ephesians--partly because the contrast of spirit is not so striking in the latter case, Colossians being far less bitterly polemic than Galatians; and more particularly because a considerable interval separates Romans from Galatians, whereas Colossians and Ephesians were dispatched by the same messenger.
In the Student's Text Book, it has been shown that the words "at Ephesus" in the first verse may perhaps be no part of what Paul wrote, but a later addition. It cannot be claimed, however, that the problem of the address has been completely solved. Without the words "at Ephesus," the address becomes very difficult. "To the saints that are and the faithful in Christ Jesus" hardly seems to make sense. The Greek words might be construed perfectly well to mean, "To the saints who are also faithful in Christ Jesus," but that is a rather unusual expression. The suggestion has been made that in the first copies of the epistle a blank space was left after "the saints that are," to be filled in with the names of the particular churches of the group which is addressed. Every church among the group would thus receive a copy with its own name inserted. The hypothesis is not altogether satisfactory. Probably we shall simply have to admit that there is an unsolved problem here.