Does God have the right to reveal how He ought to be worshipped? or has man been given authority to offer uninspired praise according to His own corrupt inventions and innovations? These are most prevalent and contentious questions which must be satisfactorily answered before God will ever be worshipped aright.
Throughout the scriptures, the people of God have been given various warnings that they must not tamper with God's Word at any time.
(Deut. 4:2) "Ye shall not add unto the word which I commanded you, neither shall ye diminish ought from it, that ye may keep the commandments of the Lord your God which I commanded you."
(Deut. 12:32) "What things soever I command you, observe to do it: thou shall not add thereto, nor diminish ought from it."
(Rev. 22:18) "For I testify unto every man that heareth the words of the prophecy of this book, if any man shall add unto these things, God shall add unto him the plagues that are written in this book: (v19) and if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life the holy city, and from the things which are written in this book."
It seems quite clear therefore from the above that the Bible remains perfect and complete for all matters of faith and practice, and therefore must not be added to. This principle also stands in regards to the singing of God's praise; for that God in His infinite perfection has not left man in the dark or ill-equipped as to how He ought to be worshipped; but rather has graciously given him a book of praise which is contained as an inseparable part of His Word known to all as the Book of Psalms.
In the New Testament the Lord Christ has given commandment and direction to the true structure of divine worship. (John 4:24) "God is a spirit: and they that worship Him must worship Him in spirit and in truth."
As we have already established, the Word of God can not be added to or subtracted from at any time and must therefore be our absolute and final authority in all matters concerning the worship of God. So how repugnant then must the ever increasing number of uninspired books of praise and hymnology be to the true and living God, who demands nothing less than true obedience and compliance to His Word.
Spirit and Truth (What?).
The word spirit spoken of by Christ in the above verse of scripture means that which is given by the Spirit of God, hence the Psalter/The Book of Psalms (2 Tim. 3:16) "All scripture is given by inspiration of God." The reference to the word truth means that all praise offered to God in worship must contain no blemishes or inerrancies but must be pure in essence. This of course can not be true of hymns and songs of human compositions, because the word of man contains innumerable doctrinal errors and also many damnable heresies. (James 5:13) "Is any among you afflicted? let him pray. Is any merry? let him sing psalms."