This is a tough one for Aaron. He was told by Moses that Hashem had chosen him to be the Kohen Gadol. Aaron never actually speaks in Torah, though he does a lot, including his negotiating with the angry tribe who thought his brother Moses was dead and now wanted some image to intercede with Hashem for them. Aaron takes their gold throwing it into a fire, not knowing that a bull would come out of it. Aaron then feared that he was not deserving, as he had participated in the creation of this Golden Calf. When he looked at the altar, it turned into the head of a bull. And far worse, his sons Nadib and Abihu, trying to get closer to Hashem on their own without permission or proper preparation, bring a fire offering into the sacred space, and though their intention may have been of the deepest kavanah, their action was inappropriate and immature, and their souls were sucked from them by a fire that entered their nostrils and Aaron’s two sons died. There is a danger in approaching Hashem without a purified spirit. Fire is coming down on us all now. Be prepared and act from positive kindness and forgive yourself.