Author: Ron Graham
Christians are to offer sacrifices to God, among these sacrifices is the sacrifice of praise, and our sacrifices are meant to please God (Hebrews 13:15-16).
Consider the sacrifice which Jesus made upon the cross. Our sacrifices must emulate the sacrifice of Christ, for by his cross he became the author and finisher of our faith (Hebrews 12:2, 13:12). Because his sacrifice pleased God, we are thereby made acceptable to God.
Christ's sacrifice was an act of obedience to God's counsel, and thus it pleased God. We must emulate this in our worship (Acts 2:23, Philippians 2:8). We are to "work out our own salvation with fear and trembling" by following our Lord's example, and offering sacrifices to God, according to God's counsel (Philippians 2:12).
Cain offered a sacrifice which displeased God. God tried to reason with him, but he could not understand why God rejected his offering, yet accepted his brother Abel's, so in jealousy he murdered his brother (Genesis 4:1-8). Abel's sacrifice was "more excellent" because he offered it by faith, and faith is that which "comes by hearing" God's word not by heeding the counsels of one's own heart (Hebrews 11:4, Romans 10:17).
Nadab and Abihu offered a sacrifice which displeased God, and they suffered the penalty of death (Leviticus 10:1-2). They offered something to God "which he had not commanded them". They did not wait for the command of the Lord (which came later as we find in Leviticus 16:12). They followed their own counsel instead of the Lord’s.
In hindsight, we realise that the offerings of Nadab and Abihu, and Cain, were rejected because they were not "types" (holy symbols) of Christ's sacrifice. But the blunder would not have been made, had the worshippers followed God's command, instead of their own think-so.
God's counsel to us, is that our sacrifice of praise should be "the fruit of lips" in other words, "singing and making melody in your heart to the Lord" (Hebrews 13:15, Ephesians 5:19). This sacrifice emulates the sacrifice of Jesus on the cross, because we do it in obedience to God’s counsel.
Some people want to add the use of musical instruments to this sacrifice of praise, but they have no authority or counsel from God. In the brackets following, I quote every passage where God commands Christians to use musical instruments in their sacrifice ( ). You'll notice the brackets are empty. To use musical instruments in worship, lacking any counsel from God, would make our worship like that of Nadab and Abihu, or like that of Cain, not like that of Jesus Christ.