Let the word of Christ - The doctrine of Christ.
Dwell in you richly in all wisdom - Abundantly, producing the spirit of true wisdom. That doctrine is adapted to make you wise. The meaning is, that they were to lay up the doctrines of the gospel in their hearts, to meditate upon them; to allow them to be their guide, and to endearor wisely to improve them to the best purpose.
Teaching and admonishing ... - See this explained in the notes at Ephesians 5:19-20. The only additional thought here is, that their psalms and hymns were to be regarded as a method of “teaching” and “admonishing;” that is, they were to be imbued with truth, and to be such as to elevate the mind, and withdraw it from error and sin. Dr. Johnson once said, that if he were allowed to make the ballads of a nation, he cared not who made the laws. It is true in a more important sense that he who is permitted to make the hymns of a church, need care little who preaches, or who makes the creed. He will more effectually mould the sentiments of a church than they who preach or make creeds and confessions. Hence, it is indispensable, in order to the preservation of the truth, that the sacred songs of a church should be imbued with sound evangelical sentiment.