And fire came out from before the Lord and consumed the burnt offering and the fat on the altar. When all the people saw it, they shouted and fell on their faces... So fire went out from the Lord and devoured them, and they died before the Lord. (Leviticus 9:24-10:2).

In the matter of just a few verses, we observe two fires come out from the LORD, one to consume the offering and the other to devour Nadab and Abihu. The first produced reverent fear. The second likely produced terror. Whether in the acceptance of their offering or in the rejection of it, the LORD manifested Himself as holy (cf. Leviticus 10:3). 

The judgment of Nadab and Abihu, the sons of Aaron, may be compared to the judgment of Uzzah in the days of King David, when Uzzah reached out his hand to steady the ark of God when it was about to slip off the ox cart. God struck him down (2 Samuel 6:1-8). Uzzah was likely clueless and careless in his actions. No motives are given in the text. He simply reacted. The sons of Aaron may have been the same way. They may have been so caught up in the drama and events of the day that they simply added something of their own to the prescribed ritual. We are not told their motives. They simply offered what God had not prescribed. 

But whether intended or unintended, whether with knowledge or without it, God would show Himself holy. As we read earlier, even when someone sinned without realizing it, this in no way nullified their guilt. While we often equate ignorance with innocence, this is not the case with God; thus, knowledge is better than ignorance. And greater knowledge is even better, especially if this implies deeper awareness of the holiness of God. 

Friends, we worship a holy God; therefore, while we stand in the light of Christ's sacrifice for our sins, let us never forget the holiness of God, in view of which we are commanded to be and live holy. Thus, the apostle Peter writes,

As obedient children, do not conform to the evil desires you had when you lived in ignorance. But just as he who called you is holy, so be holy in all you do; for it is written: “Be holy, because I am holy" (1 Peter 1:14-16).

The Lord then spoke to Aaron, saying, “Do not drink wine or strong drink, neither you nor your sons with you, when you come into the tent of meeting, so that you will not die—it is a perpetual statute throughout your generations— and so as to make a distinction between the holy and the profane, and between the unclean and the clean, and so as to teach the sons of Israel all the statutes which the Lord has spoken to them through Moses” (Leviticus 10:8-11).

It is not for kings, O Lemuel,
It is not for kings to drink wine,
Nor for princes intoxicating drink;
Lest they drink and forget the law,
And pervert the justice of all the afflicted (Proverbs 31:4-5).

The first passage above is spoken of priests. The second is spoken of kings. The priesthood and the kingship are both anointed positions, whereby God gives to the one authority in religious matters and the to other authority in secular matters. Clearly both roles require clarity of judgment and discernment. Wine and strong drink preclude clear thinking. Therefore, both priests and kings are counseled against drinking wine or strong drink.

Friends, is this counsel only for priests and kings? Shouldn't we also take this to heart? Clearly the most needful thing among believers today is clear thinking and discernment.

This is what Paul counseled Timothy: "But you, keep your head in all situations" (2 Timothy 4:5). And what was the context that prompted this counsel? Paul prophesied that people would move away from sound doctrine and the sufficiency of Scripture and go toward things that stoked their own personal interests and experiences:

For the time will come when people will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear. They will turn their ears away from the truth and turn aside to myths (2 Timothy4:3-4).

In view of this looming threat, Paul commanded Timothy to diligently study God's Word:

Do your best to present yourself to God as one approved, a worker who does not need to be ashamed and who correctly handles the word of truth (2 Timothy 2:15). 

Then, Paul commanded Timothy to faithfully, consistently, and unceasingly preach the Word:

Preach the word; be prepared in season and out of season; correct, rebuke and encourage—with great patience and careful instruction (2 Timothy 4:2).

Finally, Paul assured Timothy that the Scriptures contained within it everything that he and every other believer would ever need to do every work that pleases God:

All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God may be thoroughly equipped for every good work (2 Timothy 3:16-17).

Many people cite Ephesians 5:18-19 to encourage some mystical experience of the Spirit, but this interpretation is inconsistent with Paul's primary message, which is that edification and ministry center not on an experience but on a message, not on something mystical or ecstatic but a clear proclamation of the truth.

But then why does Paul write about being "filled with the Spirit"? Unfortunately, Paul never specifically defines how one goes about being "filled withe Spirit". However, from what we learn about priests and kings not drinking wine or strong drink because it can impair their discernment, we might also apply that here. For consider the text in question: 

And do not be drunk with wine, in which is dissipation; but be filled with the Spirit, speaking to one another in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord (Ephesians 5:18-19).

Being filled with the Spirit is contrary to the decadence, folly, and waste that drunkkenness brings. In other words, whereas wine impairs discernment, being filled with the Spirit heightens it. But again, this does not answer the "how" of being filled with the Spirit.

Now, the text says "speaking to one another in psalms and hymns and spiritual songs..." So, at least we understand that being filled with the Spirit should somehow involve our speaking and singing the various kinds of Psalms in the Bible (cf. article that convincingly argues that"psalms and hymns and spiritual songs" refer to the Book of Psalms). This is further supported by the parallel in Colossians, where Paul equates "psalms and hymns and spiritual songs" with "the word of Christ" (or "the message of Christ"):

Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord (Colossians 3:16).

Now, in this parallel passage, there is no mention of "being filled with the Spirit"; however, the corresponding description is the same. Thus, there is a strong correlation between being filled with the Spirit and being filled with "the word of Christ".

What this suggests is that Paul is not changing his tune with respect to what should be the believer's all-sufficiency for doing every good work. It is the Word of God. Even when referring to being "filled with the Spirit," he is still speaking of being filled with the Word of God. 

Friends, this somewhat long sharing began with the instruction for priests to avoid wine and strong drink so that they might have discernment. Now, I encourage you also to have discernment and to find this discernment by diligently reading, studying, and meditating on the Word of God.

And at the same time I admonish you against participating in ministries that tend to distort or askew the Word of God in preference for something new. The popular trend is away from God's Word and toward a prosperity gospel and toward ecstatic experiences and messages from self-declared prophets and apostles. You would do well to both avoid and rebuke these kinds of people.

But Aaron spoke to Moses, “Behold, this very day they presented their sin offering and their burnt offering before the Lord. When things like these happened to me, if I had eaten a sin offering today, would it have been good in the sight of the Lord? When Moses heard that, it seemed good in his sight.” (Leviticus 10:19-20)

Moses was angry with Aaron's sons because they did not eat the meat from the sin offering, as the LORD had commanded them (cf. Leviticus 6:24-30). Aaron responded that God would not be pleased if they did so in view of the tragic events of the day. It appears that all of the events, including the strange fire offered by Nadab and Abihu, as well as God's judgment of them, occurred on the eighth day of Aaron and his sons' ordination. But what did Aaron mean by his response to Moses, and which, consequently, Moses accepted.

I have discovered two views of this. The predominant view is that Aaron felt it inappropriate to eat when he was still grieving over his sons' deaths. He would perform all the other duties, as the LORD had commanded him, with respect to the offerings, even without showing any external signs of grief; however, he could not get himself to eat (i.e. "feast") on such an unfestive day, at least where he was concerned. 

Another view, espoused by Keil and Delitsche, very reputed commentators on the Old Testament, is that it was not grief that precluded Aaron's eating the meat of the sin offering but the absence of holiness. They point out that this meal was not a festive meal but a solemn one, representing God's wrath for sin. So on that count, it would have been most appropriate for Aaron and his sons to eat it in their grief, because his sons and their brothers also died in judgment for sin. But if grief was not the reason for their abstinance from eating, what could it have been? Keil and Delitsche suggest that

"the judgment in question [i.e. the death of Nadab and Abiju] was so solemn a warning, as to the sin which still adhered to them [Aaron and his remaining sons] even after the presentation of their sin-offering, that they might properly feel 'that they had not so strong and overpowering a holiness as was required for eating the general sin-offering' (M. Baumgarten)". (Keil and Delitsche on Leviticus 10:19). 

They did not eat because they were unsure of their own holiness to partake such a holy meal. Remember, Aaron reasoned, "Would it have been good in the sight of the Lord" if they were to have eaten. The context gives no sense that God considers "grieving" good. But what God considers good is those that treat Him as holy. As Moses also says earlier in the chapter,

Then Moses said to Aaron, “It is what the Lord spoke, saying, ‘By those who come near Me I will be treated as holy, And before all the people I will be honored.’” (Leviticus 10:3).

Aaron's reason for not eating was not his grief over his sons per se but because He did not want to dishonor the LORD by any lingering unholiness in himself. There is no indication that Aaron or his other sons knew that what Nadab and Abihu did was wrong, or that it was so wrong as to warrant death. They might have made the same mistake. After all, they were just being ordained into this new service now. It was not like they had years of experience in doing these ceremonies correctly. Yet, in this instance, they got a glimpse, albeit a painful glimpse, of the holiness of God. 

We find a similar kind of judgment in Acts 5, which describes the early days of the church. When two members, Ananias and Saphira, lie about their voluntary offering to the apostles, God kills them both. This causes a holy fear to descend upon everyone, both inside and outside the church. It is as if God chose to use these two as examples for the rest  of them and for the times to come, that they should always treat God as holy!

What lesson might we learn from this passage? Well, it really depends on which interpretation you choose. For instance, those that hold to the view that Aaron did not eat the sacrifice because of his grief have interpreted this passage in this way. They argue that God is not always strict in enforcing the letter of the Law because He is concerned with people's feelings. So Clarke interprets the verse this way:

"God certainly has commanded me to eat of the sin-offering; but when such things as these have happened unto me, could it be good in the sight of the Lord? Does he not expect that I should feel as a father under such afflicting circumstances?"... To human nature God has given the privilege to weep in times of affliction and distress. In his infinite kindness he has ordained that tears, which are only external evidences of our grief, shall be the outlets to our sorrows, and tend to exhaust the cause from which they flow (Clarke's Commentary on Leviticus 10:19).

But, on the other hand, if you take the view that Aaron did not eat because he did not want to sully God's holy offering, then you find a different application. In spite of our feelings, we ought to carefully obey the LORD. We should obey Him with "fear and trembling," as Paul writes in Philippians 2:12. Our obedience to God should exceed even our love for family and even our own lives. So Jesus taught,

Anyone who loves their father or mother more than me is not worthy of me; anyone who loves their son or daughter more than me is not worthy of me (Matthew 10:37).

Friends, while there are not many passages to provide insight, where there is such a divergence in interpretation, there can be room for different interpretations. But I don't know that this is one of them. If you base your interpretation on the context rather than on your own personal experience, I think you would find that one of these interpretations hold more true than the other, even though the other is held by more people. I would encourage you not to seek the interpretation that is most emotionally satisfying to you but rather to seek the one that is most steadfast to the truth and context of God's Word. 

The tabernacle is built, consecrated, and now purifed. Now God begins the era of the Priesthood. The priesthood was initiated for two very big reasons, although there are many more I don't have time to get to so here goes:

The priests were the bridge between God and the people of Israel. The Priests offered the sacrifices necessary for purification from sin from the people of Israel to God.

First, Aaron had to cleanse himself and his sons, then the tabernacle. First thing that had to be offered was the sin offering. Then the burnt offering. Then the grain offering. As I said before, God really likes BBQ! Then the consecration offering. Then the atonement offering. Then Aaron had to start the whole process all over again for the people.

And when Aaron had done all the things that he was supposed to do right, THEN God's glory showed up, fire consumed the burnt offering, and the people shouted and fell on their faces.  Now things get interesting, because Aaron's children commit the first priestly no no.

And Moses had to make it clear: The Lord spoke, and said 'By those who come near Me, I must be regarded as holy; and before all the people I must be glorified." Here is one instance where we see a connection between God's Holiness and His response to people Glorifying him. God loves our praise and Thanks! He wants to hear us testify of the glorious things he has done for us! It blesses him, it Honors him, and it brings other peoples' eyes toward Him.

God's expectation of the priest's conduct was simple:  As the primary Spiritual leaders, of the nation of Israel, the Priest defined the line between holy and unholy, clean and unclean, because the people were looking at their conduct. If the priest went to the tabernacle unclean, he would die. If he died, the people would see whether he was holy or unholy, clean or unclean.

⁹ “Do not drink wine or intoxicating drink, you, nor your sons with you, when you go into the tabernacle of meeting, lest you die. It shall be a statute forever throughout your generations, ¹⁰ that you may distinguish between holy and unholy, and between unclean and clean, ¹¹ and that you may teach the children of Israel all the statutes which the Lord has spoken to them by the hand of Moses.”

Our conduct as Christians is supposed to be above reproach so that others may see what is holy and unholy, clean and unclean. This is the first example in the Old Testament of God requiring higher standards of behavior from those individuals he has set apart. Up until now, there is a standard across the board for the nation of Israel, and now their spiritual leaders were being called out from their neighbors and set up as an example to everyone. 

There are two different stories in the OT of a high priest and his two sons who did evil before the LORD. The first is Aaron and his two sons in this section: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. (Leviticus 10)

After the death of Nadab and Abihu, their role is taken over by Aaron's other sons Eleazar and Ithamar.  The blood line of the high priest continues through Eleazer.  However, when Eli's story begins in the 1st book of Samuel, at first his geneology is not clear, it later reveals that he is from the line of Ithamar.  It is not clear how/why the high priesthood changed from Eleazer's line to Ithamar's line. However with Eli, we again see two sons that did evil before the Lord.  ¹² Eli’s sons were scoundrels; they had no regard for the LORD. .... ¹⁷ This sin of the young men was very great in the LORD’s sight, for theywere treating the LORD’s offering with contempt. (1 Samuel 2)

Unlike Aaron's sons, Eli's son were not killed immediately, but God does give Eli a prophetic message: ³¹ The time is coming when I will cut short your strength and the strength of your priestly house, so that no one in it will reach old age, ³² and you will see distress in my dwelling. Although good will be done to Israel, no one in your family line will ever reach old age. ³³ Every one of you that I do not cut off from serving at my altar I will spare only to destroy your sight and sap your strength, and all your descendants will die in the prime of life. (1 Samuel 2)

Soon afterwards the two sons die in battle with the Philistines, this is the same battle where the Philistines take the Ark of the Covenant from Isreal...After a few generations of high priests from Eli's descendents, the high priesthood is taken from Eli's family line (Abiathar) and is given to Zadok, a descendent of Eleazer...

Also in the same prophecy to Eli, God tells him...I will raise up for myself a faithful priest, who will do according to what is in my heart and mind. (1 Samuel 2:35)

As there have been faithful and unfaithful kings of Isreal, the priesthood itself also had its good and bad. Aaron himself was involved in making the golden calf and now his 2 sons are killed when they didn't follow the instructions of LORD.... But the LORD told Eli, that He will raise up a "faithful priest" who will do according to his heart and mind.

Of course, we know that this prophecy was fulfilled in Jesus Christ. The book of Hebrews says Jesus is our "merciful and faithful high priest in service to God" (Hebrews 2:17) and that He santified us not by "the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, thus obtaining eternal redemption" (Hebrews 9:12)

Thank you, Jesus, that you are BOTH our "faithful high priest" as well as the the perfect sacrificial "Lamb of God, who takes away the sin of the world!"

Yujin adds...1 Samuel 2:35 speaks of "a faithful priest... I will build him a sure house; and he shall walk before my Anointed for ever." While this may indeed look forward to Christ, who would be the ultimate High Priest-King, the most immediate referent may be Zadok, who would replace the line of Eli for high priest. And the line of Zadok would remain faithful and be perpetuated by God through the monarchies in Judah, even after the exile and into the intertestamental period (cf. Ezekiel 44:15).