John Chrysostom

"Whom we," not Angels: "teaching" and "admonishing": not imperiously nor using constraint, for this too is of God's lovingkindness to men, not to bring them to Him after the manner of a tyrant. Seeing it was a great thing he had said, "teaching," he added, "admonishing," which is rather like a father than an instructor. "Whom," saith he, "we proclaim, admonishing every man, and teaching every man in all wisdom." So that all wisdom is needed. That is, saying all things in wisdom. …

Homily on Colossians 5 ↗

Theophylact of Ohrid

We preach, but not the angels. How then after this do you consider them ministers? And he expressively said: καταγγέλλομεν – we proclaim below, that is, as if bringing Him down from on high, Not in a commanding way and not with compulsion. For this too is characteristic of divine goodness — to draw to itself not by force, but through exhortation and teaching. By "admonishing" you may understand the lessons of the active life, and by "teaching" — the explanation of dogmas. …

Commentary on Colossians ↗

Thomas Aquinas

Now he mentions its function. In regard to this he does three things. First, he indicates its function; secondly, its fruit (v. 28b), and in the third place, the help he was given (v. 29). Its function is to announce Christ; and he shows this function and the method he used: "Announce his ways among the Gentiles" (Ps 9:11); "That which we have seen and heard we proclaim also to you" (1 Jn 1:1). …

Commentary on Colossians ↗