Why this difference? Are churches of Christ too poor to afford instruments? Or do members not appreciate good instrumental music? Perhaps members of churches of Christ lack musical talent to play instruments? Maybe churches of Christ just want to be different from all others? None of these is the reason we do not accompany our singing with mechanical musical instruments.
Churches of Christ stand upon the Word of God. They seek its authority for all that they do in the work and worship of the church. They seek to return to the New Testament pattern for the church and thereby restore the Lordís church in the present day. The Apostle Paul commanded: "And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him" (Colossians 3:17). To do all "in the name of the Lord" is to do it by His authority. There is simply no authority in the New Testament for mechanical instrumental music in the worship.
The Apostle Paul also wrote: "Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord" (Ephesians 5:19). A similar passage by Paul says: "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" (Colossians 3:16).
Please note the expressions "speaking to yourselves" and "teaching and admonishing one another." This indicates reciprocal action. All the members of the congregation unite their voices in song and thereby speak, teach and admonish one another.
Please note too that an instrument is mentioned. It is not a mechanical instrument made by man such as an organ, piano, guitar, or drum. We are commanded to sing and make melody "in the heart." We accompany the "fruit of our lips" (Hebrews 13:15) with the devotion of our human hearts, instruments made by God, not man. No mention is made of man-made mechanical instruments!
If we simply follow that which God has revealed, we will use only singing by the whole church in our worship in Him. No other kind of music is commanded. To add mechanical instruments or choirs or solos is to "go beyond the things which are written" (1 Corinthians 4:6 ASV). It is to "transgress the doctrine of Christ" (2 John 9). It is to be guilty of adding to the Word of God (Revelation 22:18,19). It makes our worship vain [empty, useless] (Matthew 15:9).