Christian assemblies are beautiful expressions of harmony. When Christians gather to worship God and to share the Lord’s Supper, they make their spiritual unity very visible (1 Corinthians 10:17). That is why Paul taught Christians how the assembly should be conducted. While worship is directed to God, 1 Corinthians 14 considers how the assembly contributes to peace, order and spiritual growth. Paul emphasizes that words spoken in the assembly should be understandable (1 Corinthians 14:9, 15, 19). They should encourage and instruct (1 Corinthians 14:3-5, 12, 31). In the Corinthian situation, that principle ruled out tongue-speaking if the tongue (language) was not understood (1 Corinthians 14:28). Even inspired tongue-speakers had to submit to the principle: “Let all things be done for building up” (1 Corinthians 14:26).
If that principle applied to a miraculous gift given by God Himself, it surely applies to man-made things added from pagan worship and things borrowed from the Old Covenant (Colossians 2:16-18). The New Covenant is “not like” the Old Covenant which is now “obsolete” (Hebrews 8:9, 13). The New Covenant reveals healthy principles for unity, including the instructions given by 1 Corinthians 14. Unity is best served by the simplicity of worship in “spirit and truth” (John 4:23-24).
[May God] grant you to live in such harmony with one another, in accord with Christ Jesus, that together you may with one voice glorify the God and Father of our Lord Jesus Christ (Romans 15:5-6).