The date of the Letter cannot be exactly fixed. The
periods assigned by recent scholarship vary from 46 A.D. to 58
A.D., but the medium estimate of 53 A.D., adopted by Harnack and
Ramsay, satisfies all the requirements of the case.
The Apostle certainly visited Galatia during his second missionary tour, perhaps about 51 A. D., and, although suffering from illness, was received with enthusiasm. After a short stay he departed cherishing a joyful confidence as to his converts there. But when, less than three years afterwards, he came again, he found that the leaven of Judaism had produced a definite apostasy, insomuch that both the freedom of individual believers and his own Apostolic authority were in danger.
Even his personal presence (Ac 18:23) did not end the difficulty. Hence, possibly during his journey between Macedonia and Achaia, he sent this Letter. Its rugged and incoherent style shows that it was dictated under great stress of feeling, and the doctrine of justification by faith is stated more emphatically than in any other of his writings. But his earnest insistence upon the "fruit borne by the Spirit" proves that his ideal of practical holiness was rather strengthened than impaired by his plea for Faith as the mainspring of Christian life.
Paul's Letter to the Ephesians
This appears to have been a kind of circular Letter to the Churches in Roman Asia, and was not addressed exclusively to the Church in Ephesus.
Ephesus was a well-known seaport and the principal city in Roman Asia. It was famous alike for its wonderful temple, containing the shrine of Artemis, and for its vast theatre, which was capable of accommodating 50,000 persons.
Paul was forbidden at first to preach in Roman Asia (Ac 16:6), but he afterwards visited Ephesus in company with Priscilla and Aquila (Ac 18:19). About three years later (Ac 19:1) he came again and remained for some time—probably from 54 to 57 A. D.—preaching and arguing in the school of Tyrannus, until driven away through the tumult raised by Demetrius. He then went to Jerusalem, by way of Miletus, but was arrested in the uproar created by the Jews and was taken first to Caesarea (Ac 23:23), and thence to Rome (Ac 28:16). This was probably in the spring of 61 A.D.
Late in 62 or early in 63 A.D., this Letter was written, together with the companion Letters to the Colossians and Philemon.
Paul's Letter to the Philippians
This Letter was written shortly before that to the Ephesians, probably late in 61 or early in 62 A.D. Epaphroditus had been sent to Rome to assure the Apostle, in his imprisonment, of the tender and practical sympathy of the Philippian disciples (Php 2:25; 4:15,16). The messenger, however, fell ill upon his arrival, and only on his recovery could Paul, as in this Letter, express his appreciation of the thoughtful love of the Philippians.