Truman integrated the US military, when many churches still taught against black equality.
The churches that previously invoked Bible versus to support their discrimination against blacks, changed their church's teachings. (The Mormon church, changed first with regard to plural marriage, then to blacks. )
Try holding yourself out to be a licensed real estate agent, but when a black person asks for your services, you refuse him.
Years ago in the US, legislatures signed "fair housing" which made discrimination based on race, illegal.
Being able to rent or buy real estate, try on and buy clothes, eat in a restaurant, get a job or buy a cake are all the same in the eyes of our laws.
Inability to believe in the confines of our laws, is not a defense for not following them.
You simply cannot hold yourself out as an employer, and when a black applies, deny the job over race.
Likewise you cannot hold yourself out as a baker, and when a gay orders a cake, deny your services based on his sexual orientation.