Why Israel's Idolatry Must Be Punished
It was necessary that this sin should be punished as a testimony to surrounding nations of God's displeasure against idolatry. As the Israelites would hereafter condemn idolatry, their enemies would throw back the charge that the people who claimed Jehovah as their God had made a calf and worshiped it in Horeb. Though compelled to acknowledge the disgraceful truth, Israel could point to the terrible fate of the transgressors as evidence that their sin had not been excused.EP 225.3
Love no less than justice demanded that judgment be inflicted. God cuts off those who are determined upon rebellion, that they may not lead others to ruin. In sparing the life of Cain, God had demonstrated the result of permitting sin to go unpunished. His life and teaching led to the state of corruption that demanded the destruction of the whole world by a flood. The history of the antediluvians testifies that God's great forbearance did not repress their wickedness.EP 225.4
So at Sinai. Unless punishment had been speedily visited upon transgression, the same results would again have been seen. The earth would have become as corrupt as in the days of Noah. Evils would have followed, greater than resulted from sparing the life of Cain. It was the mercy of God that thousands should suffer, to prevent the necessity of visiting judgments upon millions. To save the many He must punish the few.EP 226.1
Furthermore, as the people had forfeited divine protection, the whole nation was exposed to the power of their enemies. They would soon have fallen prey to their numerous and powerful foes. It was necessary for the good of Israel that crime should be promptly punished.EP 226.2
And it was no less a mercy to the sinners themselves that they should be cut short in their evil course. Had their lives been spared, the same spirit that led them to rebel against God would have been manifested in hatred and strife among themselves. They would eventually have destroyed one another.EP 226.3