The Lord God made a covenant with Noah and his three sons: Shem, Ham, and Japheth. Just as when God blessed the man and the woman after creating them, He blessed Noah and his sons, and said to them. “Be fruitful and multiply, and fill the earth.” (Genesis 9:2) God gave them every moving thing that is alive for food, just as He gave the first man and the first woman the green plant. However, they were not to eat the animals while they still had life in them. If man or beast should take the life of man, God requires the life of that man or beast because man is made in the image of God. God made this covenant with Noah, his sons, and all of their descendants. He promised that never again will He cut off all flesh by the water of the flood to destroy the earth. The sign that God gave for the covenant for all successive generations is the rainbow. (cf. Genesis 9:1-17)
I do not understand the reason that the rainbow is used as a symbol for homosexuality because homosexuality brings forth no life. The rainbow is a symbol of life but it is being used to symbolize something that cannot bring forth life. The first command of God in the creation account was for the man and woman to “Be fruitful and multiply, and fill the earth, and subdue it; and rule over the fish of the sea and over the birds of the sky and over every living thing that moves on the earth.” (Genesis 1:28) God destroyed the earth with the flood, except Noah, his wife, Noah’s sons and their wives, and a pair (male/female) of every living creature on the earth. God also commanded them, “Be fruitful and multiply, and fill the earth.” (Genesis 9:2) But there has been a change, instead of commanding them to rule over the living creatures, God said that he has put the fear of man into the living creatures and God gave the living creatures to man as food, just as he gave the first man and first woman the green plant as food.
Christian brother and sister, you are not under the Mosaic covenant that was given to the sons of Israel, in the desert at Mount Sinai. First, if you are not a descendant of Israel, you were never under that covenant. Second, Paul makes it clear that Christians are not under the Old Testament law. (cf. Galatians 2:16, Romans 7:4, and Galatians 3:24-25) However, you should know that all people on the earth fall under the Noahic covenant and are to be fruitful. Therefore, homosexuality is sin for all people and for all time. We are commanded by God to “be fruitful and multiply; populate the earth abundantly and multiply it.” (Genesis 9:7)
There is forgiveness of sins for all who repent (turn from sin) and trust in the Lord Jesus Christ. (Luke 24:47)
Your Servant for Jesus’ Sake