The Lesson Of Nadab And Abihu
God has chosen to give us some valuable lessons from the Old Testament. "For whatever things were written before were written for our learning" (Romans 15:4). Nadab and Abihu were priests in the tabernacle of God under the Old Testament. One of their duties was to burn incense in the tabernacle at 9:00 AM and 3:00 PM each day. "Then Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it, put incense on it, and offered strange fire before the Lord, which he had not commanded them. So fire went out from the Lord and devoured them, and they died before the Lord" (Leviticus 10:1-2). The KJV says "strange fire". It was "strange fire" because that fire was not authorized.
Nadab and Abihu were told in offering the incense they were to "take a censer full of burning coals of fire from the altar" (Leviticus 16:12). Apparently they chose to ignore the Lord’s instructions and do as they saw fit and get the fire elsewhere. Because their sin was doing that which the Lord "had not commanded them", they were struck dead for doing so. Doing that which the Lord "had not commanded" is prohibited.