Exodus 32:11–14 (ESV)
11 But Moses implored the Lord his God and said, “O Lord, why does your wrath burn hot against your people, whom you have brought out of the land of Egypt with great power and with a mighty hand? 12 Why should the Egyptians say, ‘With evil intent did he bring them out, to kill them in the mountains and to consume them from the face of the earth’? Turn from your burning anger and relent from this disaster against your people. 13 Remember Abraham, Isaac, and Israel, your servants, to whom you swore by your own self, and said to them, ‘I will multiply your offspring as the stars of heaven, and all this land that I have promised I will give to your offspring, and they shall inherit it forever.’ ” 14 And the Lord relented from the disaster that he had spoken of bringing on his people.
This is a very important passage for understanding the way we come to God in prayer. Moses is interceding for the people of Israel by *reminding* God of his covenant with the forefathers. But God had not forgotten this covenant, nor did he need Moses to remind him. Moses is not reprimanding God, but rather appealing to him on the basis of his word.
So when the Lord “relents from the disaster that he had spoken of bringing on his people” the result is exactly what God had intended all along. He knew that he was not going to destroy them, and the gracious intervention of Moses is in accordance with God’s perfect plan.
However, in a way that I cannot fully explain, it is important to realize that God does not make idle threats. His wrath against them was real and he could have consumed them were it not for Moses’ intercession. God’s sovereignty is great enough and profound enough to include the apparent paradox between declaring his judgement against the Israelites, while knowing that he will use Moses’ intercession to save the people from that judgment.
In my mind, the only way to solve this apparent paradox is to look at the cross of Christ where God did BOTH. He judged Israel’s substitute for sin AND through that judgment he saved them and fulfilled his covenant promises. That act at the cross is the basis for God’s mercy here. He relents from this disaster here, but he carries out his word of demonstrating his wrath against sin.
Back to my starting point, regarding prayer. When we pray, we appeal to God’s word and ask him to do specific things that have a basis in his Word. When God answers our prayers, it is not because we have “changed his mind” or convinced him of something, but rather because we have been his instruments in the playing out of his eternal purposes. And yet these prayers are not just unnecessary props in God’s plan. They are a very real intercession by which God applies the grace of Christ’s atonement to situations deserving of his judgment.