|Photo credit: McMac70|
Many people have heard of the story of Noah's Ark. The inhabitants of the world are all wicked except for Noah, so G-d sends a flood to drown everyone else. It rains for 40 days and 40 nights, the water rising so high it covers the mountains. The only ones saved are Noah, his wife and immediate family, and the animals they took with them onto the ark. 
When the flood waters subside, Noah sends out a dove which brings back an olive branch. Now that they know the waters have receded and plants are starting to grow again, Noah and his family come out of the ark. G-d promises never again to bring another flood, and offers the rainbow as a symbol and a reminder of that promise.
In order to look deeper, let's switch gears. The human eye has two different overlapping vision systems: one that sees in color and another that sees in black, white, and gray. In daylight we see in full color, and under very low light we can only distinguish between light and dark colors.
|Photo credit: Madaise|
Imagine coming out of the ark, like Dorothy tiptoeing into Oz, and suddenly seeing a vibrant verdant world, with lush vegetation and a chance to start fresh. In the calm after the storm, Noah and his family are given a chance to rebuild a better world. This is part of the context of the rainbow - it is a part of the physical world but it is also in some sense miraculous, a reminder of something cynical scientists have forgotten.
After the flood Noah curses his grandson: "And [Noah] said, 'Accursed be Canaan, he shall be a slave of a slave to his brothers.' " Throughout the generations, bigots and racists have used this verse to justify the belief that some lives matter and other lives do not. Although the text doesn't speak specifically of race, after Noah's death we are told that Noah's descendants spread out into separate nations and separate countries. So it isn't unreasonable to trace the origin of racial differences back to this narrative.
And now we have all the pieces of the puzzle. Noah and his family emerge from the ark after almost a year in hibernation. Like prisoners on parole, they are free but that freedom is conditional. They have had plenty of time to think about the ills of the world they left behind, and how they will make things better when given the chance. And also there is a new perception of human differences and human skin color. Where before there was only a single family, now there is a new possibility of conflict and domination.
Onto this backdrop, G-d overlays the rainbow. Humans may appear different on the outside but beyond those differences there is an essential unity.
The symbolism of the rainbow is that of peace and reconciliation. I don't believe G-d expects or wants an "Invasion of the Body Snatchers" peace, where everyone conforms mindlessly to a single ideal. Each of us is meant to paint with our own colors. If we look at the world and see only differences, we will never escape the specter of war and the shadow of poverty. It is only by appreciating the full spectrum of humanity that we can live in the world of peace that this story asks of us.
As we reemerge from our isolation, we too have the opportunity to create a just society on the embers of our troubled past. There are no voices coming from the sky, but there are always rainbows. And if we look outward and see only dissent and division, maybe the problem isn't the external world. Maybe we just need to look at the same facts with new eyes.
 Presumably the fish didn't need to be rescued, and they are almost completely absent from the story.
 Wikipedia says the flood was a myth, not scientific fact. https://en.wikipedia.org/wiki/Genesis_flood_narrative