It is not just Leviticus it's in the new Testament.
Romans 1:27-32 (King James Version)
27And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompense of their error which was meet.
28And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient;
29Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers,
30Backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents,
31Without understanding, covenantbreakers, without natural affection, implacable, unmerciful:
32Who knowing the judgment of God, that they which commit such things are worthy of death, not only do the same, but have pleasure in them that do them.
"Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators [Gk: paramours], nor idolaters, nor adulterers, nor effeminate [Gk: catamites], nor abusers of themselves with mankind [Gk: sodomites] nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners, shall inherit the kingdom of God" (I Cor. 6:9-10).
You can say bullshit all you want , but if you read our history, we have always been a Christian Nation.