Leviticus 10

“Aaron’s sons Nadab and Abihu stood their censers, put fire in them and added incense; and they offered unauthorized fire before the Lord, contrary to his command.  So fire came out from the presence of the Lord and consumed them, and they died before the Lord.”  vv.1-2

Read chapter 10.

We find out that Aaron had four sons: Nadab, Abihu, Eleazar and Ithamar.  And here in this chapter we see the death of two of them shortly after they had just gone through their week long ordination.  There is thought that they were drunk from wine of the drink offering and therefor were intoxicated while performing the priestly service.  Shows how alcohol can effect our discernment and affect of service.  

What does "strange fire" mean?  It's referring to other fire than what the Lord commanded them to use on the altar that we just read of in chapter 9 verse 24 and also see in chapter 6 of the fire they were to use.   They used their own kindling thinking it to be the same or just as good as what God provided.  Their own thinking and justification led to their disobedience and sin.  Death seems like a harsh punishment for this disobedience but it is God's righteous judgment.  It may have seem innocent but we know that anything apart from faith (taking God at His word) is sin (Romans 14:23).  

How often does it happen today still that people assume they know what pleases the Lord because perhaps it pleases them but they aren't taking heed to God's words?  All worship that is not kindled by the Holy Spirit is "strange."