I’m reading John Murray’s Redemption Accomplished and Applied, the old classic on the atonement.The first chapter is titled “The Necessity of the Atonement.” Here, Murray seeks to answer the question after which Anselm of Canterbury titled a whole book: Why the God-Man? While he goes in to several different points, the one I’m going to talk about is the contingent absolute necessity of the atonement. Is that a mouthful? I’ll explain what it means.
The atonement is not necessary because of anything in God’s nature. Being the perfectly just judge that he is, God could have condemned everyone to hell and not have violated his nature. However, God made a promise to the serpent in Genesis 3:15:
“I will put enmity between you and the woman,
and between your offspring and her offspring;
he shall bruise your head,
and you shall bruise his heel.”
God’s promise was that the fall would be reversed, that someone would come to redeem humanity and to reconcile them to God. This is what makes the atonement necessary: God promised to accomplish it, and he is faithful to fulfill his promises. He didn’t have to make it, but he did.
As I thought about this, it struck me how the Old Testament to make a lot more sense in light of this truth.
What do we see consistently in the Old Testament narrative? We see people being unfaithful to God. They commit idolatry, they refuse to follow the law, and they even murder God’s prophets. Despite constant warnings and even chastisement and punishment for their actions, they continue in unfaithfulness. This results in the exile into Babylon.
But through all of this, God remains faithful. He brings his people back from the exile, and ultimately brings forth Jesus, who accomplishes redemption by being faithful through his life and death.
Is this just a matter of God not knowing better, just trusting that maybe they’ll do better this time? Not at all. God made a promise to redeem humanity, and no amount of unfaithfulness on the part of man can keep that from happening. That’s why God brings Israel back from her multiple captors in the book of Judges. That’s why God brings them back from exile into their land. And that, finally, is why he sent Jesus to save us.