Then Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it, put incense on it, and offered profane fire before the LORD, which He had not commanded them (Leviticus 10:1)
From the very wording of the text we can infer that the sons of Aaron, Nadab and Abihu, behaved themselves arrogantly. The text is careful to highlight and emphasize the filial relationship to Aaron, the High Priest, and although they were b'nei Aharon, sons of Aaron, they did not consult with their father before acting. Or perhaps, because they were sons of Aaron they may have felt no obligation to solicit advice from anyone else.
They had forgotten that they were merely individual members of the nation, and yet they failed to seek advice from the leaders of the nation. Instead they chose to rely exclusively upon their own reasoning and acted solely upon their own initiative. It is strongly implied that they did not even consult with each other!
The entire nation was about to experience the privilege of witnessing a revelation of G-d's closeness, and Nadab and Abihu decided to make a separate offering all their own. But our Sages are careful to point out that the priests were called to completely identify with the nation and had no standing in their own right. The whole purpose and essence of the priest is to stand in the midst of the people which accounts for their standing before G-d. And so, in their very drawing near, Nadab and Abihu were at fault. Their offering was illegal in every respect.
The Torah stresses that Nadab and Abihu each used his own firepan. In other words, our Sages understand that Nadab and Abihu did not bring their offering in vessels of the Sanctuary, but in their own vessels - without self-renunciation. As for the ketoret, the incense itself, it is the only offering that is offered as the community's obligatory offering each day and as the High Priest's obligatory offering on Yom Kippur, the Day of Atonement.
Our Sages understand that the ketoret represents a person who is completely absorbed in bringing satisfaction to G-d and represents the ideal of His requirements. But if it is offered as an expression of one's own choice, it would entail great arrogance. The Torah stresses above all that what Nadab and Abihu offered was something which G-d had not commanded them to make: asher lo tziva otam, that which He had not commanded them. Even if the details of the offering had not been forbidden, just the mere fact that G-d had not commanded that which they brought would have sufficed to make it forbidden.
There is no place in our service to G-d for subjective arbitrariness, for doing what is right in our own eyes. Even free-will offerings must comply with prescribed forms. As we have learned, the main purpose of the offerings is to draw near to G-d, to seek closeness to Him, and this closeness is attained through obedience to G-d. The pagan, through his offering, seeks to make his god subservient to his will, while we, through our offering, place ourselves in the service of G-d and accept upon ourselves His yoke which is easy, and His burden, which is light i.e. the yoke of obedience to Him and His will.
Through the offerings, we adopt the Divine imperative as a guiding light. Do not offerings of our own design and our own devising work to undermine the very truth of what the offering is intended to represent? Do not such offerings only glorify our own caprice rather than obedience to G-d? The deaths of Nadab and Abihu serve as a clear warning to future generations, barring arbitrariness and all personal caprice from the confines of the Sanctuary, whose entire purpose is to be a Sanctuary for the Word of G-d to which obedience is expected. In short, the priest's duty and function is not to introduce innovations in the Service, but to carry out G-d's commands.
We live in an age where innovation is king and is revered more than anything else. We obsess and wring our hands about our "relevance." And to remain relevant we are forced to innovate and reinvent ourselves every few years, because we have no idea of what to do in a world that places a higher value on style than substance and on experience than the truth. After all, without innovation and seeker friendliness, how do we function in a world that refuses to tolerate a worldview that makes exclusive claims on personal allegiance, obedience, and faithfulness?
The answer today: innovate. In other words, lighten the load. But not in the way Y'shua taught. Although He invited the weary and heavy laden to take up His yoke, His yoke involved much more than most were (and still are) willing to bear. No, we must innovate. Why? Because we believe, really believe, that our weakness lies in the fact that our routines are too old, the music too dull, the programs too scant, the parking lots too empty, and that most of the problems are simply a matter of style and comfort.
As I heard one minister put it years ago: G-d rests too inconsequentially upon us. His Word, if taught at all, is insufficient. The riches of the Messiah are entirely searchable. We claim that G-d is the center of our worship and yet, if that is true, we can't help but wonder why there is so much that is unauthorized, superfluous, and counterproductive to true worship orbiting this center.
What do we need to rediscover, or rather Who?
How about G-d in His grace, truth, and awesome, holy presence? How about the G-d who struck down and consumed those well-meaning innovators, Nadab and Abihu, on the first day of their service in the sanctuary? How about the G-d Who can whet our lost appetites for the truth once again? Innovative programs, no matter how radical, change overnight and will change, and change again. How about the G-d Who can change human nature?
How about dispensing with the cocktail party-atmosphere that serves up pleasantries while avoiding unpleasantness and starting with a humble return to the G-d Who demands that we offer ourselves as living sacrifices on His altar, Who demands that we stop conforming to the patterns of this world and start being transformed by the renewing our minds so that we can discern His perfect will for ourselves and for those who are dead while they live?
Of course, it's difficult to miss the irony of just how innovative that would be today.
Let him who is convinced that his views are true and right express them . . . at every opportunity . . . without considering how much support or how much opposition he will encounter. Only falsehood is in need of many supporters in order to win the day; falsehood must have the authority of numbers to make up for what it lacks in justification. Truth, by contrast, will always prevail, even if it takes time. Noble, courageous and pure, expressed with all the fiery zeal and conviction and with all clarity of sure awareness, stated again and again at every opportunity, truth will ultimately gain respect and admiration even of those who do not accept it. The only truth that can be lost beyond recall is that truth whose adherents no longer have the courage to speak up candidly on its behalf. Truth has never gone down in defeat as the result of opposition, it has done so only when its friends are too weak to defend it. - R' S.R. Hirsch