I’m just so disappointed that it’s assumed, before even starting, that all great authors are straight white male Christians and then goes on to talk specifically at them (not really to them, because privilege is bad, I guess) about how awful they are for being born to privilege, as if they had any more power over that than I did being born female. It’s treating it’s supposed audience like the stereotype it tells them not to use in their own writing. As another comment said, write them as people first. Figure out their motivations, what drives them, where they started from and why they are where they are, and use that to figure out where they’re going and how they react to stimulus. While there are some things that will be quite different, so many things will be the same as long as you understand the character’s motivations and desires.