What does the Bible say about Nadab and Abihu?

The incident involving Nadab and Abihu, recorded in Leviticus 10:1-2, serves as a grave warning about the holiness of God and the seriousness of proper worship. These two sons of Aaron offered 'strange fire' before the Lord, which was something God had not commanded. This act demonstrated a lack of recognition for the holiness and authority of God, leading to dire consequences. Their actions highlight that nothing is trivial when it comes to God's commands and the worship due to Him. The severity of their punishment underscores the reality that God is not to be treated casually or with irreverence.