15 And let the peace of God rule in your hearts, to which also you were called in one body; and be thankful.
16 Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.
17 And whatever you do in word or deed, do all in the name of the Lord Jesus, giving thanks to God the Father through Him.
peace (v.15) — within the believer AND among all believers
Whenever anything takes place which would create anxiety or perplexity, making it difficult to know how to act, the peace of Christ is to settle the matter, controlling and directing the heart. — Colossians, by W.E. Vine, page 365
God (v.15) — should be “Christ”
rule (v.15) = act as an umpire, arbitrate, decide
word of Christ (v.16) — His revealed will
dwell (v.16) = to live in as a home
richly (v.16) — in quantity and degree — fully and constantly
in all wisdom (v.16) — goes with “teaching and admonishing”
admonishing (v.16) = warning, exhorting, encouraging, reproving
While the leading idea of psalmos (psalms) is a musical accompaniment and that of humnos (hymns), praise to God, oide (spiritual songs) is the general word for a song, whether accompanied or unaccompanied, whether of praise or on any other subject. Thus it was quite possible for the same song to be at once a psalm, hymn, and a spiritual song. In the text, the reference to psalms, we may suppose, is specially, though not exclusively (1 Corinthians 14:26), to the Psalms of David, which would early form part of the worship of the Christian brotherhood. On the other hand, hymns would more appropriately designate those hymns of praise which were composed by the Christians themselves on distinctly Christian themes, being either set forms of words or spontaneous effusions of the moment. The third word, spiritual songs, gathers up the other two, and extends the precept to all forms of songs, with the limitation however, that they must be spiritual — Ephesians and Colossians in the Greek New Testament, by Kenneth S. Wuest, page 227.
grace (v.16) — grace, with the additional idea of gratitude
to the Lord (v.16) — should be “to God” — for God’s glory
in the name of the Lord Jesus (v.17) — in conformity to His character, with the realization of His authority and presence