“Let the word of Christ richly dwell within you, with all wisdom teaching and admonishing one another with psalms and hymns and spiritual songs, singing with thankfulness in your hearts to God.” (Colossians 3:15)
Let me pick up our observations on this important verse. Check the previous post here for context of the opening words.
Paul follows up with two participles: “teaching and admonishing.” Some contend that these participles receive imperatival weight from the previous imperative (“Let . . . dwell,” cf. NRSV), yet this seems doubtful and it is best to find their meaning in subordinate relationship to that imperative. Just what is that relationship? They could indicate the means by which we are to let the word of Christ dwell in us richly, or the mode in which this dwelling becomes reality, or they could indicate the result of letting that word so dwell within us. There is obviously a evenly divided split in opinion regarding the function of these participles in the sentence. All in all the best option seems to view them either as expressing means or mode, the difference in meaning being negligible.
These two actions have already been used to describe Paul’s personal ministry in 1:28, though in reverse order. Now they are to characterize what the local believers are to practice with “one another.” The plural form of the reflexive pronoun (“one another”) can function also in a reciprocal manner and pictures the back-and-forth nature of the fellowship intended. In speaking of “teaching” Paul uses a word which is used at times to speak of official teaching of doctrine within the church and the scope of those who are to undertake this ministry is limited (1 Tim. 2:12). But here the word is clearly broadened to include all members of the body of Christ. The word “admonishing” comes from a word which in turn comes from a compound of “mind” and “to place/put.” Thus the literal sense of the word is “to put in mind.” It means to admonish, to warn, or to instruct in the sense of “giving instructions in regard to belief or behavior.” Being coordinate (“and”) with one another they present a positive (“teaching”) and more negative (“admonishing”) side to the total ministry of the word among the believers.
As one can quickly see this ministry must be undertaken “in all wisdom.” This is the third time this precise phrase has been used in Colossians (1:9, 28; 3:16). Most telling is its use in 1:28 where it similarly tells us the manner in which Paul undertook these same two ministries. Wisdom is a significant theme in this letter (1:9, 28; 2:3, 23; 3:16; 4:5), playing a more prominent role than it does in Ephesians (1:8, 17; 3:10). This may be due to a special emphasis on wisdom among the false teachers in Colossae (2:23). Paul has in view “all” or every form or expression of God’s wisdom.
 Lightfoot, 222; Lohse, 150; Robertson, 4:505.
 Wallace, 652.
 Harris, 168.
 Moo, 228; O’Brien, 207.
 Alford, 3:238; Wright, 144.
 Robertson, Grammar, 690.
 Thayer, 429.
 Friberg, 273.