"It's none of you business why anyone thinks gay marriage should not be allowed."

Actually, that is exactly what the justices look to when the Supreme Court considers 1st Amendment cases involving religion. While you Strick say you are opposed to gay marriage because it goes against tradition, the tradition of which you speak is rooted in religion. When you factor in who the proponents of the gay marriage constitutional amendment are (religious groups), then it does rise to the standard of the 1st.