So although it might have been a symbol used to point to a denomination filled with a radical diversity, or a pointer to the diversity of God's creation, nonetheless God's beautiful promise and our circumstances have another meaning.
The rainbow drapery on the cross should remind all that in that cross there is hope for those who are sexually broken. The rainbow in Scriptures is one of God's pointers to the cross. It is a remembrance of mercy and forgiveness on God's part. It is God's gift after wrath, yet it is a remembrance that the flood of water covered sin and killed the sinner. But there is another flood that washes clean and renews and transforms the sinner. That is the blood of Jesus.
"If you address as Father the One who impartially judges according to each ones work, conduct yourselves in fear during the time of your stay on earth; knowing that you were not redeemed with perishable things like silver or gold from your futile way of life inherited from your forefathers, but with the precious blood, as of a lamb unblemished and spotless, the blood of Christ." (1 Peter 1: 17-18"
Because the LGBTQ community has chosen the rainbow symbol and now it is connected to the cross, as it should have been, they are combined symbols that the Holy Spirit can use to both enlighten and convict the sinner of their sexual brokenness. The Holy Spirit is always wooing us to Christ. The Father is always pleading with us to come to Christ. The Israelites in the desert looked to a bronze serpent and were healed. May the community that we are all in prayer for look to the cross of Jesus understanding that he forgives, saves and transforms.