This is a question most often asked. We feel that there are very sound reasons for NOT using physical instruments in our worship. Contrary to what some claim, our practice is based on what the New Testament actually SAYS rather than what it is silent about. That is, we believe that a clear picture emerges that shows worship occurring in a NEW TEMPLE that replaces the OLD Temple of Judaism. Please consider the following:
First, the issue of music in worship must be understood in the context of a New Covenant. (1) Worship patterns in the NEW will be different than in the OLD (John 4:21ff). (2) The physical forms of the OLD were symbols of their true realities in the NEW (Hebrews 10:1ff). (3) When the NEW came, the symbols were no longer needed. That is, the physical Jewish Temple itself has been replaced by the bodies of Christians (1 Corinthians 6:19). Each Christian is a NEW living "house of prayer" (1 Thessalonians 5:17) in which the Spirit of God dwells (1 Corinthians 6:19, Acts 2:38) and helps in prayer (Romans 8:26). Also, this NEW TEMPLE is mobile and can worship God at any place and at any time (e.g., John 4:21ff, Acts 16:25, James 5:13) as contrasted with the fixity of the OLD Jewish Temple. It is clear that a better and more spiritual Temple has come into being under the NEW Covenant.
In the same way, as physical instruments of music were inside the OLD Temple for praising God (2 Chronicles 29:25ff, Psalm 150, Psalm 147:7), spiritual instruments are inside the NEW Temple for praising God. In Ephesians 5:19, singing is to be accompanied by the vibrating of the strings of the "HEART." [The Greek word psallo, which is translated "making melody" in Ephesians 5:19, literally means to "twang, pluck, or vibrate." Just what is to be vibrated immediately follows (i.e., heart).] Like the examples above, the outward of the Old is again replaced by the inward of the New. Hence, singing accompanied by a spiritually-tuned, vibrant heart is the style of musical praise now!
Second, in another strand of thought, the very PRIESTHOOD of the Old Covenant has also been replaced by Christians themselves. NEW sacrifices are now offered that are spiritual in nature (1 Peter 2:5). A person's daily life is put on the altar (Romans 12:1). This offering will naturally include sacrifices of praise ... specifically, the fruit of lips that confess His name (Hebrews 13:15). Only speaking, singing or chanting exactly fulfills this (Colossians 3:16, Ephesians 5:19, 1 Corinthians 14:15), but a harp, horn, drum or tambourine, etc., cannot. Again, the material has been replaced by a more spiritual way.
Third, if musical instruments in Christian worship was just an "optional matter," it seems that those converts coming from Judaism would naturally and immediately use it in worship from the start. After all, inspired texts --such as Psalm 150-- encourage the use of instruments in praise to God! Yet with these texts right before their very eyes, the Jewish-converts just sang and never brought over the instrument (neither did pagans) as over 500 years of early church history confirms! This surely shows that a new pattern or design for worship has come about (See McClintock and Strong Encyclopedia, Vol. VIII, p. 739; Schaff-Herzog, Vol. III, p. 1961, "When did churches start using instrumental music?" at www.christianitytoday.com.)
CONCLUSION: A coherent picture emerges that shows that worship via the physical, ritualistic and symbolic style of the OLD TEMPLE has been replaced. NOW there is a NEW living Temple that is a mobile, dwelling place for God, where daily spiritual sacrifices of praise are offered and singing is accompanied by the vibrating strings of a joyful heart (not a harp, etc.). Something new and better has arrived that makes the former way obsolete. Hence, using physical instruments in praising God is conceptually "out-of-place" in New Covenant worship. It changes the design.
1) In light of the conclusion above, using musical instruments in Christian worship would move us backward toward the physical style of the Old Temple ... clearly a move in the wrong direction.
2) Since "just singing" was the norm for at least 500 years after Pentecost, such reinforces the conclusion and makes this practice a move in the right direction.
Answer: It takes positive facts to make a case for something. When all the facts are assembled, often a picture of significance emerges such as that of a NEW TEMPLE replacing the OLD TEMPLE. This becomes a guiding scriptural principle that allows us to compare and contrast the Old with the New and see a cohesive picture unfold. This design and the corroborative evidence of church history is what our case is based on and not "the absence of evidence" (i.e., "silence"). However, it is true that the picture that emerges EXPLAINS the silence of the New Testament on the use of instruments in worship. It would be obviously "out-of-place" with regard to the NEW pattern for worship. In context, silence acts to help solidify an understanding ... but acting alone it can neither affirm nor deny a thing.
Link to other Evidences by John Lankford