By your logic, the first part of the First Amendment has no meaning.
The 14th Amendment Section 1 states: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
Notice that neither race, creed or color are mentioned. It is case law which has set forth that race and color are protected classes.
Neither of them are in conflict with Christian religion as generally recognized (I am not going down the rabbit hole of a neo-Nazi forming their own church and stating that blacks and whites cannot marry each other).
Not only the Catholic Church, but a multitude of evangelical and fundamental churches hold that a homosexual marriage is not within the definition of marriage. This is not just some Catholic quirk; short of the mainline Protestant churches, no one else is holding that 2 men or 32 women can marry each other. To put it in the vernacular of a few years ago, Adam and Eve yes. Adam and Steve, no. Non biblical.
The issue is one of whether the religion of Christianity (or for that matter, Islam), or the religion of secularism and hedonism is the source of law in the land.
By your logic, a girl wanting an abortion in a town that has only one doctor can force that doctor to abort her child.
You really want to go down that path?