8 Then God said to Noah and to his sons with him, 9 “Behold, I establish my covenant with you and your offspring after you, 10 and with every living creature that is with you, the birds, the livestock, and every beast of the earth with you, as many as came out of the ark; it is for every beast of the earth. 11 I establish my covenant with you, that never again shall all flesh be cut off by the waters of the flood, and never again shall there be a flood to destroy the earth.” 12 And God said, “This is the sign of the covenant that I make between me and you and every living creature that is with you, for all future generations: 13 I have set my bow in the cloud, and it shall be a sign of the covenant between me and the earth. 14 When I bring clouds over the earth and the bow is seen in the clouds, 15 I will remember my covenant that is between me and you and every living creature of all flesh. And the waters shall never again become a flood to destroy all flesh. 16 When the bow is in the clouds, I will see it and remember the everlasting covenant between God and every living creature of all flesh that is on the earth.” 17 God said to Noah, “This is the sign of the covenant that I have established between me and all flesh that is on the earth.”
They say an optimist sees a glass half-full. A pessimist sees a glass half empty. An engineer sees a container twice as large as it needs to be. We can each look at the same thing and see something different, and perhaps all be right. When you look in the sky on a day when a rain shower has passed through, what do you see? Does light refract through raindrops to create a multihued band of light in the sky? That is one way to describe a rainbow. It is indeed a physical phenomenon which involves light and water interacting. We can describe it that way. But is that all there is for us to see?
Genesis 9 would have us see something else which is also true: a promise from God in that rainbow, a promise not to repeat what happened in that flood so many years ago. God will destroy His creation eventually. Peter says it will happen by fire, so I suppose that is technically keeping the covenant God makes here. But I think there is something more than that. In the flood, God made a serious effort to wipe out the evil from the world, washing it away with a deluge. Only Noah and his family were left. God promises not to take that approach again. He does wash away evil, even uses water, but he does so now through Baptism.
The next time it rains and you look into the sky to see this rainbow, marvel at its beauty, explain the physics of light refraction to your children if you are able, but most of all, remember and praise God for His promise. He has another solution to the evils of this world in which we live.
“For Christ also suffered once for sins, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit, 19 in which he went and proclaimed to the spirits in prison, 20 because they formerly did not obey, when God’s patience waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight persons, were brought safely through water. 21 Baptism, which corresponds to this, now saves you, not as a removal of dirt from the body but as an appeal to God for a good conscience, through the resurrection of Jesus Christ, 22 who has gone into heaven and is at the right hand of God, with angels, authorities, and powers having been subjected to him.” I Peter 3:18-22