Well, being older is part of what gives him a different viewpoint, possibly even a more mature one, but it doesn't mean you're wrong. What he needed as a child in a father figure (and other things) may have been different than what you needed, and he might be more forgiving of your stepfather's faults.

I'll tell you flat out, though, if all you say is true about your stepfather, it sounds like you have a much more accurate perspective, in my opinion. There's no way that kind of behavior didn't have a negative impact on you two.

Does he agree with you all that happened? Is it possible you actually witnessed more of it than he? The way you capitalized "FANATIC" suggests to me it wasn't a healthy religious life. Abusers often start out seemingly "good" or "normal." They don't always abuse right from the start, and the abuse is often subtle or causes you to question if it really is abuse at first.

I hope you don't mind me asking, but what does your brother think makes him the "best thing that ever happened" to you? How can he think your family was better off with someone who abused your mother, controlled her, cheated on her and nearly killed her?