I think if most people in the US are honest, the first exposure they have to spiritual morality is church of some kind either going, meeting people who proselytize, or as I now interpret the church IS the people who believe in God and talk about redemption through Christ.
A lot of what people take for granted about morality actually comes from the Bible. Blackstones formulation comes from Sodom and Gamorrah. Which is the foundation of th "innocent until proven guilty" axoim.