Worship is done unto God. Of course, being God, He knows exactly what He wants. He also knows our sins, weaknesses, limitations, tendencies, pride, and He knows what we need. So, by His word He has intently, firmly, and so often expressed His will regarding how man is to relate to Him, live for Him, and worship Him rightly in all ages. A faithful reading of His word would conclude that nothing more, nothing less, and nothing else than what is revealed in His truth is appropriate for true worship. That essentially describes the Regulative Principle.

For scriptural supports, notice the insistence to careful observance within just a few verses from Deuteronomy chapter 4:

¹ “Now, O Israel, listen to the statutes and the judgments which I teach you to observe, that you may live, and go in and possess the land which the Lord God of your fathers is giving you. ² You shall not add to the word which I command you, nor take from it, that you may keep the commandments of the Lord your God which I command you…

…⁶ Therefore be careful to observe them…

…⁹ Only take heed to yourself, and diligently keep yourself, lest you forget the things your eyes have seen, and lest they depart from your heart all the days of your life. And teach them to your children and your grandchildren,…

…¹⁵ Take careful heed to yourselves, for you saw no form when the Lord spoke to you at Horeb out of the midst of the fire, 16 lest you act corruptly and make for yourselves a carved image…

…²³ Take heed to yourselves, lest you forget the covenant of the Lord your God which He made with you, and make for yourselves a carved image in the form of anything which the Lord your God has forbidden you. ²⁴ For the Lord your God is a consuming fire, a jealous God.”

God and His messengers instruct and plead this way constantly.

Genesis 4:3-7

³ And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the Lord. ⁴ Abel also brought of the firstborn of his flock and of their fat. And the Lord respected Abel and his offering, ⁵ but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell. ⁶ So the Lord said to Cain, “Why are you angry? And why has your countenance fallen? ⁷ If you do well, will you not be accepted? And if you do not do well, sin lies at the door. And its desire is for you, but you should rule over it.”

Exodus 20:2-8

² “I am the Lord your God, who brought you out of the land of Egypt, out of the house of bondage. ³ “You shall have no other gods before Me.

⁴ “You shall not make for yourself a carved image—any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; ⁵ you shall not bow down to them nor serve them. For I, the Lord your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations of those who hate Me, ⁶ but showing mercy to thousands, to those who love Me and keep My commandments.

⁷ “You shall not take the name of the Lord your God in vain, for the Lord will not hold him guiltless who takes His name in vain.

⁸ “Remember the Sabbath day, to keep it holy.

Exodus 25:40

And see to it that you make them according to the pattern which was shown you on the mountain.

1 Samuel 15:22

²² So Samuel said: “Has the Lord as great delight in burnt offerings and sacrifices,

As in obeying the voice of the Lord? Behold, to obey is better than sacrifice,

And to heed than the fat of rams”.

Matthew 15:1-9

¹ Then the scribes and Pharisees who were from Jerusalem came to Jesus, saying, ² “Why do Your disciples transgress the tradition of the elders? For they do not wash their hands when they eat bread.”

³ He answered and said to them, “Why do you also transgress the commandment of God because of your tradition? ⁴ For God commanded, saying, ‘Honor your father and your mother’; and, ‘He who curses father or mother, let him be put to death.’ ⁵ But you say, ‘Whoever says to his father or mother, “Whatever profit you might have received from me is a gift to God”— ⁶ then he need not honor his father or mother.’ Thus you have made the commandment of God of no effect by your tradition. ⁷ Hypocrites! Well did Isaiah prophesy about you, saying: ⁸ ‘These people draw near to Me with their mouth, And honor Me with their lips, But their heart is far from Me. ⁹ And in vain they worship Me, Teaching as doctrines the commandments of men.’ ”

Colossians 2:23

²³ These things indeed have an appearance of wisdom in self-imposed religion,…

Also, there were the corrections given in 1 Corinthians chapters 13 and 14 against abuses of spiritual gifts in the church, confusion, and lack of edification.

Positively, the Lord’s word instructs us regarding what to do in worship.

John 4:23-24

²³ But the hour is coming, and now is, when the true worshipers will worship the Father in spirit and truth; for the Father is seeking such to worship Him. ²⁴ God is Spirit, and those who worship Him must worship in spirit and truth.”

Hebrews 10:25

²⁵ not forsaking the assembling of ourselves together, as is the manner of some,

1 Timothy 4:13

¹³ Till I come, give attention to reading, to exhortation, to doctrine.

2 Timothy 4:2-5

² Preach the word! Be ready in season and out of season. Convince, rebuke, exhort, with all longsuffering and teaching. ³ For the time will come when they will not endure sound doctrine, but according to their own desires, because they have itching ears, they will heap up for themselves teachers; ⁴ and they will turn their ears away from the truth, and be turned aside to fables. ⁵ But you be watchful in all things, endure afflictions, do the work of an evangelist, fulfill your ministry.

Ephesians 5:19

¹⁹ speaking to one another in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord, ²⁰ giving thanks always for all things to God the Father in the name of our Lord Jesus Christ, ²¹ submitting to one another in the fear of God.

Matthew 21:13

¹³ And He said to them, “It is written, ‘My house shall be called a house of prayer,’ but you have made it a ‘den of thieves.’ ”

Luke 21:4

⁴ for all these out of their abundance have put in offerings for God, but she out of her poverty put in all the livelihood that she had.”

Baptism (Matt 28:19; Acts 2:38–39) and the Lord’s Supper (Matt 26:26-30; 1 Cor 11:23–26).

It is exceedingly clear from God’s word that the Lord requires a right heart and complete obedience unto His instructions and principles for acceptable worship in Jesus Christ. The particular circumstances and particular details which are ours to decide upon, such as the hour to begin worship, and such, are to be done according to the Lord’s principles, with wisdom, love, diligence, and as 1 Corinthians 14:40 states, “Let all things be done decently and in order.” The Lord is certainly worthy of such. Gladly, to pursue His will in this way takes up all of our heart, soul, mind and strength without the need to deviate.

(It is therefore our conviction that as God’s word regulates everything in worship, there is no place for any alternate things, and we are thereby guarded from various evils, idolatry, carnality, man-centeredness, partiality, factions, usurpation of authority, authoritarianism, man’s (stubborn) tradition, self-righteousness, legalism, antinomianism, man’s philosophy, humanism, man’s (carnal) wisdom or presumptuousness, self-sufficiency, pride, manipulation, intimidation, unscriptural practices, entertainment, emotionalism, sensationalism, subjectivism, irrationalism, a lack of self-control, disorderliness, confusion, chaos, esotericism, and any falsehoods.