This fear didn't last very long, as we see in Numbers 16:41
But on the next day all the congregation of the people of Israel grumbled against Moses and against Aaron, saying, “You have killed the people of the Lord.”and the people of Israel blame Moses and Aaron?
One can only shake one's head in wonder at this - but there's an important lesson to be learned from this. Israel had direct, visible evidence of the presence of their Lord and God through a cloud that led them by day, and a pillar of fire by night, manna to feed them every day - and still they did not believe it was God who was working in their midst and leading them. I can only surmise that - for some reason - they thought that Moses and Aaron had the power to command all these wonders which kept them alive while dealing with their opponents using earthquakes and fire from the sky.
This is an important lesson to remember in our present days when we wonder why more people do not believe - if Israel, whom God made His chosen people - repeatedly refused to believe, is it any wonder that people in our present day don't believe either?
Whatever the truth behind Israel's unbelief is, the events of the prior day repeat themselves again, but this time with much more dire results. After the congregation of Israel assembled against Moses and Aaron, a cloud covers the tent of meeting, and the glory of the Lord appears. And what does the Lord have to say this time?
“Get away from the midst of this congregation, that I may consume them in a moment."
And behold, the plague had already begun among the people. And he [Aaron] put on the incense and made atonement for the people. And he stood between the dead and the living, and the plague was stopped. Now those who died in the plague were 14,700, besides those who died in the affair of Korah.
It makes you stop and think of what's in store for the people in our present day who mistreat and abuse the faithful ambassadors God has sent them to keep them safe and fed...