The safety of refusing to serve the minority
The Bible-based laundry list in the article of reasons not to serve someone at your place of business is amusing, but it serves another point: such discrimination seems highly unlikely to happen because, well, you couldn't stay in business, right? Exclude divorcees, people with tattoos, anyone who illegitimate (or has illegitimacy in their family tree going back generations)? Potential customers would laugh in your face (or spit in it) for asking, and your doors would shortly close.
No, the only time such discrimination works is when a majority chooses to take a "principled" stand against a minority -- where it won't hurt too much, won't alienate too many others, won't overly damage the bottom line, where there are plenty of Our Kind around to fill in the gaps and maybe even reward us for our moral behavior with additional custom.
That's a big part of what's pernicious about the "religious freedom" law in Indiana, and, to similar laws when proposed: they provide a vehicle for not just (to be charitable) for person religious expression, but for the majority to safely discriminate against a minority who can't strike back, e.g., gays.
It's not a sign of moral courage, but of bullying.