Sometimes we are guilty of worshiping the right God the wrong way. God does not like when we do this because it mars His holy character. It does not show Him the proper respect that is due Him. This is what is happening in Leviticus 10:1-3. In this passage Aaron’s two oldest sons offered “unauthorized [or strange] fire” before the Lord. For this action the Lord struck them down and they died. What!! Is this not a bit extreme? I mean were they not just trying to spice up the worship service a little bit?
There are many reasons why this is not extreme. Perhaps the main reason is that God had repeatedly said that everything connected with the tabernacle worship must be done exactly according to the pattern that was provided for Moses on the mountain. God expects to be obeyed. God expects to have no rivals. God expects this because he is God. This, ultimately, is what is at stake here. Is God really God?
Moses and Aaron realize this. This is why Aaron does not mourn, publically at least, the deaths because, “by those who come near to me I must be regarded as holy, and before all the people I must be glorified.”(v.3) How do you think we might be able to regard God as holy today?