More than the letter to the Ephesians, the twin letter of the Colossians, this letter is about the position of Christ and there is more emphasis on doctrinal truths. The letter of Ephesians speaks more about the position of the body of Christ.
This letter was probably written at the same time as the Ephesians letter in the first half of Paul's two-year captivity in Rome (AD 61-63; Acts 28). Both letters are apparently conveyed by Tychicus, who would also tell the addressees more about Paul's circumstances (Eph. 6:21 and 22 and Col. 4:7 and 8). The Philippians letter was written at the end of that two-year period. Thus the three congregational letters for the body of Christ were written from captivity. The letter to Laodicea mentioned at Colossians 4:15 and 16 is probably the letter we know as the Ephesians letter. It is believed that the words "[at Ephesus]" (Eph. 1:1) were not originally there (hence it is in square brackets). The letter to Ephesians should therefore certainly not be seen in connection with the letter to Ephesus from Revelation 2:1-7.
Although Paul wrote letters to Laodicea and Colossians, we find no record of his visit to those cities in the book of Acts; let alone his work there. He probably never even visited both cities! In Colossians 1:4 and 9 he writes that he "heard" of the faith of the Colossians (cf. also Eph. 1:15). That is not how Paul expresses himself in the Philippians letter, which he had seen (Acts 16:12-40 and Phil. 1:30). In addition, the Colossians had come to know the "grace of God in truth" through the ministry of Epaphras (Col. 1:6 and 7).
Both the Ephesians and the Colossians are therefore less 'personal' than the Philippians.
A. 1:1-2 Letter style and greeting.
B. 1:3-8 Report and messages by Epaphras.
C. 1:9-2:7 Paul's concern for the Colossians and his prayer that they might know the mystery.
D. 2:8-23 Doctrinal correction insofar as one did not live from the truth, as it appears in the Ephesians letter. Died with Christ.
D. 3:1-4:1 Doctrinal correction insofar as one did not live from the truth, as it appears in the Ephesians letter. Raised with Christ.
C. 4:2-6 Paul's concern for the Colossians and his request for their prayer regarding his preaching of the mystery.
B. 4:7-9 Report and reports by Tychicus and Onesimus.
A. 4:10-18 Letter style and greeting.
It has already been noted in the chapter about the Ephesians that the three captivity letters are each written to saints and believers "in Christ"; while his earlier municipal letters are mainly addressed to 'congregations at ...'. Another characteristic is that they reveal the (hidden) plan of God with regard to the church today, the body of Christ. In the letter to Colossians the basis of this 'doctrine' concerning the body of Christ is completed. So these letters inform us of our position and walk.
A third characteristic of these letters is that Paul describes in detail his prayer for the believers. Much more than in the other congregational epistles (where Paul especially gives thanks, if he spoke about his prayer at all), in these three epistles his prayers (in the sense of asking) come to the fore. And what he asks for is always the same: knowledge (Greek: epignoosis, deeper knowledge, knowledge that is higher than general knowledge, acknowledgment):
Ephesians 1:17 "that . . . God . . . give you the Spirit of wisdom and of revelation, to know him rightly" (lit. "give you a spirit of wisdom and revelation in his knowledge") ;
Philippians 1:9 "this I pray, that your love may abound still more in clear understanding and in all subtlety" (lit., "may abound more in knowledge") and
Colossians 1:9 "to pray for you, and ask that you may be filled with the knowledge of His will."
In these texts, therefore, the same Greek word epignoosis is always used. If we really want to "discern what matters" (Phil. 1:10), it is necessary to pray for this knowledge. The glorious things of the mystery message are so hidden from our minds in the first place that God did not just let them be recorded. No, whenever His servant had to write about it, it was accompanied by a prayer to receive that knowledge. For example, why did Paul rejoice in his great battle (Col. 2:1ff); what does it mean that we are raised with Christ (Col. 3:1); what are the blessings associated with our hidden position in Christ (Col. 3:3) and what exactly is our hope (Col. 3:4)? By fulfilling knowledge we come to understand it!
"To them God willed to make known how rich the glory of this mystery is among the Gentiles: Christ among you, the Hope of glory (...) Now that you have received Christ Jesus the Lord, walk in Him..." (chap. 1:27 and 2:5).