Right, and if one is born again of the Spirit, regardless whether he or she is ethnically Jewish, he or she is a Jew, a Jew of God, of God's Israel. As Paul also says, "...no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God" (Romans 2:28-29).Whoever is not born again of the Holy Spirit of God, all of such (though they believe) are not in the KoG, but are only running parallel to it. John 3:3-8.
As Rom. 8:9 says: "Now if any man have not the Spirit of Christ, he is none of his".
Now...
"Jesus Christ the faithful witness, the firstborn of the dead, and the ruler of kings on earth" (Revelation 1:5)... firstborn in the same sense that David was as God said of him in Psalm 89:27 ~ "And I will make him the firstborn, the highest of the kings of the earth." David, as should be quickly pointed out, was the youngest of all his brothers. So 'firstborn' must mean something other than that, well, either David or Jesus was literally born first, the eldest. And the verses above should be good indicators of what 'firstborn' really means... Basically, it means preeminence. David was preeminent over Israel in the Old Testament. Jesus is preeminent over and King of God's Israel, which consists of Jew and Gentile... all those called by God and born again of the Spirit. Paul says it well in Colossians 1:15-20...Jesus is the FIRST born of that of a NEW Creature. The FIRST of a brand new SPIRITUAL race of beings who IS REALLY Eternal and Immortal.
Jesus NOW IS NOT Jew, Gentile, Male or Female!!!
"(Jesus) is the image of the invisible God, the firstborn of all creation. For by Him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities ~ all things were created through Him and for Him. And He is before all things, and in Him all things hold together. And He is the head of the body, the church. He is the beginning, the firstborn from the dead, that in everything He might be preeminent. For in Him all the fullness of God was pleased to dwell, and through Him to reconcile to Himself all things, whether on earth or in heaven, making peace by the blood of his cross."
In view of this, it goes without saying, certainly, that Jesus was the firstborn in a far greater sense than David... king David was what we call a shadow, or type, of the greater reality to come, King Jesus. The whole of the Old Testament ~ Moses and all the prophets ~ is really about Jesus (Luke 16:29, 24:27, 44; John 1:45, 5:46; Acts 28:23). As the writer of Hebrews says, "Long ago, at many times and in many ways, God spoke to our fathers by the prophets, but in these last days He has spoken to us by his Son, whom he appointed the heir of all things, through whom also He created the world."
Grace and peace to all.

after the great flood, God promise to Noah never do it again, but he could do Great drought after the great flood.