Then Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it, put incense on it, and offered profane fire before the Lord, which He had not commanded them.
2 So fire went out from the Lord and devoured them, and they died before the Lord.
3 And Moses said to Aaron, “This is what the Lord spoke, saying:
‘By those who come near Me
I must be regarded as holy;
And before all the people
I must be glorified.’”
So Aaron held his peace.
The Regulative Principle of worship is a principle based on the sufficiency of Scripture which teaches that everything we do in the worship of God must have positive warrant in His Word. Every part of worship must be expressly commanded by God or be clearly deducible from Scripture. It is not enough to say God has not forbidden it, therefore it is allowed. Worship is never merely allowed by God; it is always required, and if He does not require it, we should not give it. An example of this is found in Leviticus 10:1-3 when Nadab and Abihu were killed by God for offering ‘strange fire’ before Him. They used something God had not authorised and when God explains their error in v1, ‘which he commanded them not’, He means they did something He never told them to do.
This is seen again in Jeremiah 7:31 when God is condemning the idolatry of His people: ‘And they have built the high places of Tophet, which is in the valley of the son of Hinnom, to burn their sons and their daughters in the fire; which I commanded them not, neither came it into my heart’. God is teaching us in such places that it is His prerogative alone to appoint what should be given to Him as worship. When we apply this to the singing of praise in worship we should ask first, Why do we sing? Because God commands us. Then, What will we sing? Again we will sing only what God tells us to sing. If we sing Psalms it is because God tells us to and if we want to include any other songs in the worship of God we must show that God commands us to do this or else we are in breach of His Law.
…So does the New Testament now command (not merely allow) the church to sing something other than inspired materials of praise in the worship of God? The text most often offered as warrant for the introduction of uninspired materials of praise is Ephesians 5:19 and its parallel reference in Colossians 3:16. A study of this verse will sufficiently answer our question. We will open up the text and develop the argument under six
…The Greek words used by Paul are psalmos meaning psalm; humnos meaning hymn; and ode meaning song. A common mistake made in interpreting these words is to take what these words have come to mean in the 21st century and impose these meanings on the text. Then a psalm may be one of the compositions in the Biblical Psalter; a hymn might be something written by Isaac Watts; a song is then linked with something lighter – perhaps a chorus. Then having imposed this understanding of the words on the text, the conclusion is made that songs other than the inspired songs of the Biblical Psalter are commanded for worship today.
If you were in Ephesus when Paul’s letter arrived, and you had a Bible in your church, it was a Septuagint. As you browsed through the Book of Psalms three terms would keep appearing in the titles and you would be quite familiar with them – psalmos, humnos and ode. In 67 Psalms the word psalmos is found eg Psalm 23; in 6 titles the word humnos appears eg Psalm 8; in another 35 Psalms ode is in the title eg Psalm 45. Furthermore, in 12 Psalms the words psalmos (psalm) and ode (song) are found together in the title e.g. Psalm 65, and in 2 titles psalmos (psalm) appears with humnos (hymn) eg Psalm 6. If you had studied the title of Psalm 76 all three terms are found in the Septuagint title, ‘For the end, among the hymns, a psalm for Asaph; a song for the Assyrian’. The Ephesian Christian would know that one Psalm could be a psalm and a song, or even a psalm and a song and a hymn together. All three terms were found in the titles of the Psalms and even in the title of one composition in the Book of Psalms. Paul exhorted them in biblical terms they were familiar with.
…Someone might still object, ‘But why does Paul employ three terms in Ephesians 5:19, if what you are saying is that all three refer to the Book of Psalms? Is that not a bit redundant, a bit like saying Psalms, Psalms and Psalms?’ In answer to this objection we have already seen that the Psalms themselves do this, eg the title of Psalm 76, Psalm 65 in the title and v1. In addition to this we should also note how frequently in Scripture God employs a three-fold statement to refer to the same thing, a Biblical triplet of terms. So laws can be ‘commandments, statutes and laws’ (Gen.26:5), miracles can be ‘Miracles, wonders and signs’ (Acts 2:22), and prayers can be ‘Prayers, supplications and intercessions’ (1Tim.2:1). So why should it be thought a strange thing that God should use three terms in the one verse to refer to His divinely inspired book of Psalms?
—Rev. Gavin Beers, “Psalms Only—Tradition Or Scripture?”]