23.

God burned 250 people to death for burning incense

In his last killing, God showed whose side he's on by opening up the ground and burying alive the leaders that opposed Moses (along with their families). And it made quite an impression on everyone.

All Israel that were round about them fled at the cry of them: for they said, Lest the earth swallow us up also. Numbers 16:34

But they were safe, at least for the moment, because God had his mind on other things. Remember Moses's original plan for dealing with Korah's rebellion? He told him and his associates to burn incense before the Lord and let God choose who is holy.

This do; Take you censers, Korah, and all his company; And put fire therein, and put incense in them before the LORD to morrow: and it shall be that the man whom the LORD doth choose, he shall be holy. 16:6-7

But then God came up with the burying alive thing and the censer-swinging prayer contest was put on hold.

In the meantime, 250 of Korah's followers did as Moses asked and burned some incense. So God burned them all alive to teach them a lesson or something. (If you do what he says, he'll burn you to death?)

There came out a fire from the LORD, and consumed the two hundred and fifty men that offered incense. 16:35

At least I don't have to guess the number of victims this time.