The rainbow does not enter the Book of Genesis as a compliment to humanity. It appears after the world has been drowned in a cataclysm of judgment. 

            The Hebrew word qeshet, translated “rainbow,” is the ordinary word for a warrior’s bow. The image is striking: the bow that might have been drawn in judgment now hangs in the clouds.

            The rainbow is therefore not the celebration of humanity looking proudly at itself. It is the sign of frightened and guilty creatures being permitted to look upward and discovering that above them stands the promise of God.

            Nothing in the Genesis story suggests that humanity has suddenly improved. Before the flood, “the wickedness of man was great in the earth” (Genesis 6:5). Afterward, God still says that “the imagination of man’s heart is evil from his youth” (Genesis 8:21). Same song, different verse.

            The flood has not repaired the human heart. What changes is the word God speaks.

“I establish my covenant with you.”

            That is the turning point. The future of creation will not rest upon Noah’s improved performance or humanity’s promise to do better. It will rest upon God’s promise.

“I establish my covenant with you and your descendants after you, and with every living creature that is with you.”

            Notice the direction. God does not say, “If you establish yourselves with me.”

He says, “I establish my covenant with you.” The promise comes from outside us. Then God attaches a sign to His promise:

“I set my bow in the cloud, and it shall be a sign of the covenant between me and the earth” (Genesis 9:13).

The rainbow is, therefore, not a statement about humanity. It is a sign of God’s faithfulness.

“I will remember my covenant.”

That is the heart of it.

            Our culture has attached other meanings to the rainbow, and even churches may turn it into a badge of their own moral virtue. But every badge of righteousness eventually becomes law, dividing the approved from the unapproved. The church need not compete for possession of the symbol. It need only hear what God says through it.

           The rainbow belongs first to God. And what it signifies is mercy in the midst of judgment.

That pattern will run through the whole biblical story. Humanity will continue to fail. The Tower of Babel will rise, a monument to pride. Israel will proclaim its adherence to the law even as it wanders and stumbles in sin. Kings who claim God’s anointing will abuse their power. The law will relentlessly accuse. Human righteousness is continually exposed for what it is: an impossible project of self-justification.

            And still God speaks the living Word of steadfast love and mercy. The Old Testament rainbow, therefore, points beyond itself toward the Cross.

            At Golgotha, judgment is not avoided by redefining sin or declaring it no longer matters. Sin is carried in the body of Jesus. Once again, God places the future where sinners cannot secure it themselves: outside us, in Jesus Christ, crucified and risen.

            The gospel, therefore, has the same character as the promise to Noah. God does not ask the sinner to construct a new self or manufacture a future. 

            The rainbow hangs in the sky, and the Cross was planted in the earth because sinners cannot secure their own future before God. We look to neither as a symbol of human pride nor as an assurance of a cheap grace that merely leaves the old sinner undisturbed. They point away from us altogether.

 

The bow declares that God has bound himself to his promise.

 

The Cross declares how far that promise will go.

 

            And in baptism that promise comes all the way to you: you have died with Christ; you have been raised with Christ; your sins are forgiven. Your future is secure in Christ. Faith is simply being caught and held by that word.

            For the promise finally rests neither upon the sincerity of the believer nor upon the righteousness of the church, but upon the faithful God who binds himself to sinners by a word they did not earn, cannot deserve, and cannot undo.