Parshat Shemini relates to the joyous time when the Jews finally started the long-awaited service in the Mishkan, but it is interrupted with the disturbing death of Aharon's two oldest sons, Nadav and Avihu. Their sin was that they wanted to show their love for Hashem so much that they took it upon themselves to take incense, Ketoret, and burn it on their own. The Torah then says that a fire “came out from before Hashem and consumed them.” It seems strange that the same fire that two Pesukim earlier came down to burn the offerings was the same fire that came down to kill Aharon's sons! Why did they specifically die with fire, which is what they tried to use to serve Hashem? The Rashbam helps us understand the reason why Aharon’s sons were wrong by explaining that they were not authorized to bring the offering, and that their bringing it minimized the miracle of the fire coming down from the sky. However, although they died, the Pasuk says they died “before Hashem,” which some commentaries explain to mean that they at least tried to do a good thing, and were worthy of dying before Hashem. The lesson from all of this is that although we as Jews could have been instructed to burn all the offerings ourselves, there were some that were left for Hashem to burn Himself. Doing, or "burning" things ourselves minimizes the very essence of those commandments. We have the guidelines of the Torah, not because they make sense to us and would do them anyway, but because Hashem wants us to do things a certain way. The point of the fire was to show us that Hashem would use fire for us, unless we make Him use that very fire on us by altering the “plan.” The important lesson for us is that we all need to observe the commandments correctly so that they strengthen the fires within us, and not let the fire of Torah burn without us!