The Priests of Israel had just been completed, and the glory of God had been seen, and the people awed by His glory.  Now something tragic happens.  Two of God’s priests, two of the sons of Aaron do something that God did not tell them to do.

And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which He commanded them not.  And there went out fire from the LORD, and devoured them, and they died before the LORD.  Then Moses said unto Aaron, This is it that the LORD spake, saying,
“I will be sanctified in them that come nigh Me, and before all the people I will be glorified.”
And Aaron held his peace.
Leviticus 10:1-3

Nadab and Abihu offered “Strange fire before the LORD.”  They had entered the tabernacle with this offering, with a fire they had not taken from the altar at gate, but from some other source. It was not consecrated fire.  It was of their own doing; and of their undoing.

There are things we are told to do; and their are things we are told not to do.  We generally do not want anyone telling us we cannot do something; or telling us to do something. God is faithful to Himself, and His word.  So we can be confident that He will be faithful to us as well.

The two sons of Aaron made a fire to take into the tabernacle, and they had not been told by God to do so.  Have we, as Christians done some things that on the outward appearance look like a good thing?  If it is practical it must be okay. “Right?” I am going to let the Holy Spirit and the word of God guide you into what those things might be.

“I will be sanctified in them that come nigh Me, and before all the people I will be glorified.”  The word from God after the death of the two die in the tabernacle.  God is His own defender of His Glory and His  holiness.  We must remember this as we worship God in our times of personal, and our churches times of worship.

We worship the God who has made the heavens and the earth, and everything in the universe.  The seen and the unseen were all made by Him through His Son Jesus who has been with Him through eternity.  Our God is a consuming fire (Hebrews 12:29).  We must know that, and be obedient to Him, and very respective of His glory and holiness.

Nadab and Abihu should have known better than to offer something strange, unwanted by God; and so should every believer in Jesus Christ.