These are the opening verses of Leviticus chapter 10:
Now Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it and laid incense on it and offered unauthorized fire before the LORD, which he had not commanded them. And fire came out from before the LORD and consumed them, and they died before the LORD.
(Leviticus 10:1-2 ESV)
The two oldest sons of Aaron bring an offering before the Lord, but they do not do so in the way that God requires, and the die because of it. In our (post) modern Christian culture, this seems unthinkably harsh. “How could a loving God punish someone so cruelly for simply trying to worship Him in a different way?” We might ask.
But we live in a time when our expressions of worship are shaped almost exclusively by our own desires and experiences. We only sing songs that we like, we ignore aspects of God’s character that seem to go against the way that we like to think about Him, we fit Jesus and His church into our schedules, and we find the preachers that most satisfy our itching ears and ignore the words of our own local pastors.
In short, we worship God the way that we want to, and I fear that most times, we offer “unauthorized fire” before Him and expect Him to simply accept it. But Scripture is clear that to worship God on our own terms is to not really worship God at all. It is idolatry, and He will not share His glory with another. Therefore He will not accept our selfish and prideful offering. Instead, our attitude must be that of the Psalmist who says:
Deliver me from bloodguiltiness, O God,
O God of my salvation,
and my tongue will sing aloud of your righteousness.
O Lord, open my lips,
and my mouth will declare your praise.
For you will not delight in sacrifice, or I would give it;
you will not be pleased with a burnt offering.
The sacrifices of God are a broken spirit;
a broken and contrite heart, O God, you will not despise.
(Psalm 51:14-17 ESV)
There is only one way to offer right sacrifices before God, and that is to do so through Jesus Christ. He is the Way, the Truth, and the Life. In the Old Testament, God required that His people worship Him through the sacrificial system, so that they might be ceremonially clean before Him. Now, we are to come through Christ so that we might be actually clean before Him. But we must come humble, as Psalm 51 says. There is no “going through the motions” with God. We must become broken over our sin and dependent on God alone for our salvation, our sanctification, and our eternal satisfaction.
When we come before God the way He requires, we bring HIm the most glory and He gives us the most joy.