Leviticus 10:1 New International Version (NIV)

The Death of Nadab and Abihu

10 Aaron’s sons Nadab and Abihu took their censers, put fire in them and added incense; and they offered unauthorized fire before the Lord, contrary to his command.

The fire on the alter was to never go out. It was holy. When the two sons brought fire from another source, it was unholy. Also, the time was not right. The office of the priest was to be upheld with the greatest respect. The two sons were acting in disrespect. They were not following the conduct of worship precisely. As leaders, there is a special responsibility to obey God. In a leadership position, there is a possibility of leading people astray. Leaders who are commissioned by God to lead or teach have a special responsibility to take their role seriously and to not take it for granted. Stay faithful to God and follow his instructions.