Genesis 9:13 I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth.
The skeptic may look at this verse and reply, “The rainbow is simply a product of sunlight refracted in air-born water molecules, it is created by rain not God.” Well... the first part is correct, but the second betrays a misunderstanding of the text.
The key to understanding this passage is sunlight. There shouldn't be any, at least not enough for a rainbow. In fact, God's justice requires that the earth be covered by rainclouds until life is drowned out. Sunlight peeking through the clouds creating a rainbow is evidence God's justice is being withheld by God's mercy.
The story began in Genesis 6:1-8. God was finished with the earth and mankind, His justice seemed to have overridden the mercy He had extended to Adam, Eve, and their children. In 6:7 He declared the final, absolute destruction of all mankind including Noah and his family. Justice destined all to die in a cataclysmic flood with no rainbows visible. No sunlight would pierce these clouds.
But then in Genesis 6:8, just as in the Garden Of Eden, God allowed mercy to peek through the foreboding clouds of justice and lifted this judgment from Noah and his family. Noah had been condemned with the rest of humanity, so Noah wasn't freed from justice because of his goodness, he was freed by God's grace purchased on his behalf by Jesus' gospel work. Jesus future death was symbolized by the offerings in Genesis 8:20-22. Mercy withheld justice.
Noah and his children were lawbreakers just like the people who drowned in the flood, and the people who would come after them... us. Justice demands a flood again. Every moment of everyday since Noah, God's stormy justice has been withheld by His mercy in Jesus Christ. The sun always shines through the storm clouds somewhere on earth, so there is ever a bow in clouds on the mercy side of the storm... our side of the storm. These rainbows send us the mixed message of justice and mercy: we deserve destruction, but Jesus has secured mercy for us.
One more thing... when hurricanes hit our coasts I periodically hear the inland preachers of doom point the finger of judgment at us coastal dwellers and say our judgment is deserved. They are right, at least as far as they go. But the rest of the story is (and this is when the preacher of doom becomes a gospel preacher) that if justice had its way the storm would extend from the coast to them, and then past them to the whole earth... because they are cut from the same cloth we are... Adam's cloth. We all deserve the storm, but when the storm stops short the message is mercy. Mercy in Jesus Christ. The rainbows surround us, everyday, every moment. Thank God for His covenant of Mercy! Genesis 9:8-17