For this discussion C.O.D. stands for 'cause of death' not 'cash on delivery'. However the idea of payment due upon receipt can be applied in a sense.
As this post unfolds I hope to show how it relates to the question presented in my last post: "What is God willing to accept from me/you?". The text is found in Leviticus 10:1-3, using the immediate context of chapters 8,9,&10 and an expanded context of Exodus 28,29,&30.
Leviticus 10:1-3
1)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. 2)So fire came out from the presence of the LORD and consumed them, and they died before the LORD. 3) Moses then said to Aaron, "This is what the LORD spoke of when he said: "'Among those who approach me I will show myself holy; in the sight of all the people I will be honored.'" Aaron remained silent.
Basic info: Aaron was the high priest. Nadab and Abihu were his sons. God had commanded Moses to consecrate them for the priesthood. The pattern for this consecration is recorded in Exodus chapter 28 and was followed in every detail in Leviticus chapter 8. The ordination ritual included ceremonial washings, putting on the appropriate clothing including undergarments, and the application of blood to various body parts. The duties of the priests were also clearly outlined.
Clearly scripture states that the fire offered by Nadab and Abihu was unauthorized. It does not say they were unauthorized to use fire. As sons of Aaron they were of the lineage chosen by God to be priests. By the physical ordinances, they had been consecrated/sanctified by following Moses' instructions. One of their duties was to keep the fire burning at all times. Fire in a censor was the means of lighting lamps and incense. However this time, the fire offered was not as God had commanded. The problem was not with the fire alone, it was with the priests who offered it.
Some insight as to the condition of Nadab and Abihu may be gleaned from the words the Lord spoke to Aaron in Leviticus 10:8-10. 8) Then the LORD said to Aaron, 9) "You and your sons are not to drink wine or other fermented drink whenever you go into the Tent of Meeting, or you will die. This is a lasting ordinance for the generations to come. 10) You must distinguish between the holy and the common, between the unclean and the clean, and you must teach the Israelites all the decrees the Lord has given them through Moses."
The death sentence was not put upon them because they were drunk, disorderly, or confused about what they were doing, although I believe they were all of those things. They died due to what came before being drunk, disorderly, and confused. They were consecrated on the outside, but not in their hearts. They were appointed by God, they were dressed right, they had been sprinkled with blood, they were in the right place, they had the right tools, but they did not reverence God. Why else would Moses remind Aaron of what God had spoken? (see verse 3 of our text)
For sake of space and time I'll cut right to the application of this passage. A person may be saved, called, and appointed by God. He/she may be properly instructed on required duties, and may be following orders to the letter. He/she may be dressed appropriately and fully equipped for service. But, their service will not be blessed if there is no reverence of God in their heart. The inner man must be clean in order to properly hallow the Almighty.
As my pastor would say,"now I'm going to meddle a little bit". It does not matter how holy you look, act, or talk. It doesn't matter how well you teach or preach. It doesn't matter how many gifts of the Spirit you operate in, or how many fruit of the Spirit you think you have, if you heart is not clean your service is merely a strange offering. Instead of ushering in the blessing of God you will only bring reproach upon yourself. Continuing in this deceitful charade will certainly hasten your spiritual death and perhaps even your physical death.
God will accept no offering without purity, no service without holiness, no action that does not honor Him. What is God willing to accept? Obedience and that with a clean heart.