Overenthusiastic, overconfident leaders can do great harm. Before they became leaders they understood events through their own perspective. What they did not understand is that leadership involves relating to many perspectives, many interest groups and points of view. That does not mean that you try to satisfy everyone. Those who do so end up satisfying no one. But you have to consult and persuade. Sometimes you need to honor precedent and the traditions of a particular institution. You have to know exactly when to behave as your predecessors did, and when not to. These call for considered judgment, not wild enthusiasm in the heat of the moment.
Nadav and Avihu were surely great people. The trouble was that they believed they were great people. They were not like their father Aaron, who had to be persuaded to come close to the altar because of his sense of inadequacy. The one thing Nadav and Avihu lacked was a sense of their own inadequacy.
To do anything great we have to be aware of these two temptations. One is the fear of greatness: who am I? The other is being convinced of your greatness: who are they? I can do it better. We can do great things if (a) the task matters more than the person; (b) we are willing to do our best without thinking ourselves superior to others; and (c) we are willing to take advice, the thing Nadav and Avihu failed to do.
People do not become leaders because they are great. They become great because they are willing to serve as leaders. It does not matter that we think ourselves inadequate. So did Moses. So did Aaron. What matters is the willingness, when challenge calls, to say “hineni – here I am.”