And when this epistle is read among you, cause that it be read also in the church of the Laodiceans; and that ye likewise read the [epistle] from Laodicea.
Note 14 at Col 4:16: Paul's instruction to the Colossians to have the Laodiceans read this letter and that they, in turn, were to read the letter Paul had written to the Laodiceans illustrates that the truths contained in this epistle are not limited to just the Colossians. Any believer can benefit from these truths. This letter is to all Christians of all times.
Note 15 at Col 4:16: F.C. Synge in his commentary on Colossians states, "There is in existence a letter to the Laodiceans, surviving only in Latin, but evidently originally written in Greek. It is found in many copies of the Latin Bible from the sixth century to the fifteenth. But in all that time no scholar accepted it as genuine, and no one accepts it now.
"The reference here may be to a lost letter; or, as had been conjectured, the letter may be the letter we know as Ephesians, for this might be a circular letter [see Life for Today Study Bible Notes, Introduction to Ephesians]. It contains no personal greetings and, moreover, many of the best MSS. omit the words 'at Ephesus' in the opening verse" (Philippians and Colossians: Introduction and Commentary, p. 98; brackets mine).