Biblically speaking, the rainbow is the sign of a covenant that God made with the whole earth: He will never destroy the earth again with a flood. The rainbow is literally correlated to rainfall.
God made this covenant, with the rainbow as the token, after the waters of the flood receded and Noah and his family exited the ark. God said, “I establish my covenant with you: Never again will all life be destroyed by the waters of a flood; never again will there be a flood to destroy the earth. . . . This is the sign of the covenant I am making between me and you and every living creature with you, a covenant for all generations to come: I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the earth. Whenever I bring clouds over the earth and the rainbow appears in the clouds, I will remember my covenant between me and you and all living creatures of every kind. Never again will the waters become a flood to destroy all life. Whenever the rainbow appears in the clouds, I will see it and remember the everlasting covenant between God and all living creatures of every kind on the earth” (Genesis 9:11–15).
God made this promise, signified by the rainbow, not only to mankind but to “every living creature . . . the birds, the livestock and all the wild animals, all those that came out of the ark . . . every living creature on earth” (Genesis 9:9–10). The covenant is perpetual, enduring to all generations. Never again will there be a worldwide flood.
The colors of the rainbow are sometimes used as a symbol of “gay pride.” This began in 1978 when an artist named Gilbert Baker designed and made a flag for the homosexual community in San Francisco. Baker’s original design had eight colors, and he assigned a meaning to each one: hot pink (sexuality), red (life), orange (healing), yellow (the sun), green (nature), turquoise (art), indigo (harmony), and violet (spirit). Subsequent designs sported seven and then six colors. Rainbow flags and banners, as used by the LGBTQ+ community, represent diversity, hope, and social action.
There are other rainbow flags and banners that have nothing to do with the homosexual culture. For example, the Hawaii Ko Aloha Flag has nine colored stripes representing the islands that were inhabited before Western civilization arrived. Another example is the flag of the International Order of the Rainbow for Girls, a Masonic organization whose banner represents seven different virtues.
The rainbow is God’s creation. We naturally delight in it. There is something awe-inspiring in the appearance of a rainbow after a storm. It is good and right that we rejoice in the rainbow as a God-ordained symbol of God’s faithfulness and mercy. The attempt of some to co-opt the colors for their own purposes does not diminish the beauty and wonder of what God has made.