I say you misuse scripture because you fail to understand the various covenants God has made with men and how those covenants present different relationships in the Bible. You misunderstand scripture because you don't grasp that the Sinai/Mosaic Covenant is done while the Abrahamic and New Covenants still function. These two covenants are covenants to all people who God has chosen.
You fail to realize that the US was never Christian, it was always secular. You fail to accept that even Christians are sinners who do sinful things that God calls them to repent of or be disciplined. Failing to recognize all persons as equal is a sin. Failing to see a person as a brother and sister in Christ and instead seeing them by the color of their skin is a sin.
Galatians 2:11-21
11 But when Cephas came to Antioch, I opposed him to his face, because he stood condemned. 12 For before certain men came from James, he was eating with the Gentiles; but when they came he drew back and separated himself, fearing the circumcision party. 13 And the rest of the Jews acted hypocritically along with him, so that even Barnabas was led astray by their hypocrisy. 14 But when I saw that their conduct was not in step with the truth of the gospel, I said to Cephas before them all, “If you, though a Jew, live like a Gentile and not like a Jew, how can you force the Gentiles to live like Jews?”
15 We ourselves are Jews by birth and not Gentile sinners; 16 yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified.
17 But if, in our endeavor to be justified in Christ, we too were found to be sinners, is Christ then a servant of sin? Certainly not! 18 For if I rebuild what I tore down, I prove myself to be a transgressor. 19 For through the law I died to the law, so that I might live to God. 20 I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me. 21 I do not nullify the grace of God, for if righteousness were through the law, then Christ died for no purpose.
Genesis 17:5-8
5 No longer shall your name be called Abram, but your name shall be Abraham, for I have made you the father of a multitude of nations. 6 I will make you exceedingly fruitful, and I will make you into nations, and kings shall come from you. 7 And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you. 8 And I will give to you and to your offspring after you the land of your sojournings, all the land of Canaan, for an everlasting possession, and I will be their God.”
Galatians 3:10-14
10 For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.” 11 Now it is evident that no one is justified before God by the law, for “The righteous shall live by faith.” 12 But the law is not of faith, rather “The one who does them shall live by them.” 13 Christ redeemed us from the curse of the law by becoming a curse for us—for it is written, “Cursed is everyone who is hanged on a tree”— 14 so that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we might receive the promised Spirit through faith.
There is no longer any separation. Yet you promote separation that God does not promote.