In the sixth aliyah (section) of Parshas Tetzaveh, there are specific instructions regarding the korban tamid (daily offering) that should be brought on the mizbeach. The mizbeach was a significant place of communication with Hashem, as a fire would come down to consume the offerings that they brought. This obvious expression of Hashem's presence creates a necessary yirah and restraint. This essential yirah is the opposite of Nadav and Avihu's unrestrained ahavah when they rushed into the mikdash in order to bring the ketores. They did not act appropriately for that time, but that is the way that we should behave on Purim, expressing the passion and desire to find Hashem in a time when He is not openly revealed.